Application Instantiation Error: Could not connect to MySQL Topic is solved

[jasper_coetzee]

I installed the facebook pixel plugin on my site (am-tech.co.za). Everything was still working fine, but the moment that I activated the plugin, the site stopped working. Initially it just gave a blank screen, but now it reports "Error displaying the error page: Application Instantiation Error: Could not connect to MySQL." I have been Googling, and got to the post "viewtopic.php?t=971497", where a person had the same problem.

I followed the advice of @Webdongle to download the Forum Post Assistant, but after installing the fpa-en.php and running it, I did not get any result. The feedback was "This page isn’t working; am-tech.co.za is currently unable to handle this request; HTTP ERROR 500.

I also tried the method that the originator @terciodejesus found to work, but with no result.

Problem is that I do not have a backup. Stupid, I know.

Please help.

[jasper_coetzee]

I can just add that I recently also installed a facebook pixel on another Joomla 3 site of mine (where I had backups) with no problem whatsoever.

[sozzled]

Why are you using an old, outdated version of J! 3.x (J! 3.4.3 was released 7½ years ago) on the target website? What version(s) of J! are you using on the other J! 3.x website?

What is the name of the "Facebook pixel" plugin that you are using? Maybe you should unistall it?

[jasper_coetzee]

Hello @sozzled,

Thank you for reaching out to me.

Your question about the Joomla version is a good one to which I do not have a proper answer. The other site was recently updated to version 3.9.28.

The plugin's full name is facebook-pixel-for-joomla-pixel-914037906211194.zip.

I will gladly uninstall the plugin if I can get into the website's back end, but I cannot. Is there a way to get in which I do not know?

I am going to list the last lines of the error log here (I found out about this on another post).

[31-Aug-2021 12:28:25 UTC] PHP Fatal error: Call to undefined method JApplicationAdministrator::isClient() in /home/kigtkyoe/public_html/plugins/system/officialfacebookpixel/officialfacebookpixel.php on line 36

I copied the code in the officialfacebookpixel.php from line 33 to 52:

33 public function onBeforeCompileHead() {
34 $app = JFactory::getApplication();
35
36 if ($app->isClient('administrator')) {
37 return true;
38 }
39
40 if ($this->params->get('pixel_id', false)) {
41 $pixel_id = $this->params->get('pixel_id');
42 $this->injectPixelBaseCode($pixel_id);
43 }
44
45 $is_form_submitted = $app->getUserState(FacebookPluginConfig::SUBMIT_JOOMLA_CONTACT_FORM, false);
46 if ($is_form_submitted) {
47 // Reset the user state
48 $app->setUserState(FacebookPluginConfig::SUBMIT_JOOMLA_CONTACT_FORM, false);
49
50 $script = Pixel::getPixelTrackLeadCode(array(), true);
51 $this->injectPixelTrackCode($script);
52 }

I hope this will shed light on the issue.

[sozzled]

I'm guessing that this plugin is Official Facebook Pixel which was de-listed from the JED for a "General Guideline Violation" (whatever that means).

So, we don't know if this plugin is compatible with J! 3.4.3 (and you still haven't offered an explanation about why you're running an unsupported version of J! that's 6 years or 71 releases older than the latest one). We guess that this plugin is causing a database connection error.

You can disable the plugin by going into the filesystem and renaming the PHP file. I don't know what kind of plugin this and so I can't tell you exactly where to look.

Another way of disabling the plugin is to make a small change in the database. You want to look at the _extensions table, locate the record corresponding to that plugin and change the value in the enabled column from 1 to 0.

It's usually easy enough to find the version of J! installed on a domain unless the site owner protects the file that contains the information. If you, too, would like to know how to do find this information you can do what I did and ask Google.

[sozzled]

Thanks for the update. The construction

Code: Select all

$app->isClient('administrator')

was introduced in J! 3.7 (which explains why it won't work with J! 3.4.

[jasper_coetzee]

My reason for the old Joomla version is simply that I did not think it matters that much. However, when I get the site working I will immediately arrange for my upwork man to update the site.

I tried renaming the php file, but it did not work.

I exported the database, and will try that solution.

I will report back. Thank you very much so far. It gives me hope.

[jasper_coetzee]

Is this where I need to make the change in the database?

(10123, 'PLG_SYSTEM_OFFICIALFACEBOOKPIXEL', 'plugin', 'officialfacebookpixel', 'system', 0, 1, 1, 0, '{\"name\":\"PLG_SYSTEM_OFFICIALFACEBOOKPIXEL\",\"type\":\"plugin\",\"creationDate\":\"June 2018\",\"author\":\"Facebook\",\"copyright\":\"Copyright 2004-present Facebook. All Rights Reserved.\",\"authorEmail\":\"\",\"authorUrl\":\"www.facebook.com\",\"version\":\"1.0.3\",\"description\":\"PLG_OFFICIALFACEBOOKPIXEL_XML_DESCRIPTION\",\"group\":\"\",\"filename\":\"officialfacebookpixel\"}', '{\"pixel_id\":\"914037906211194\"}', '', '', 0, '0000-00-00 00:00:00', 0, 0);

[jasper_coetzee]

Is this where I need to make the change in the database?

(10123, 'PLG_SYSTEM_OFFICIALFACEBOOKPIXEL', 'plugin', 'officialfacebookpixel', 'system', 0, 1, 1, 0, '{\"name\":\"PLG_SYSTEM_OFFICIALFACEBOOKPIXEL\",\"type\":\"plugin\",\"creationDate\":\"June 2018\",\"author\":\"Facebook\",\"copyright\":\"Copyright 2004-present Facebook. All Rights Reserved.\",\"authorEmail\":\"\",\"authorUrl\":\"www.facebook.com\",\"version\":\"1.0.3\",\"description\":\"PLG_OFFICIALFACEBOOKPIXEL_XML_DESCRIPTION\",\"group\":\"\",\"filename\":\"officialfacebookpixel\"}', '{\"pixel_id\":\"914037906211194\"}', '', '', 0, '0000-00-00 00:00:00', 0, 0);

[jasper_coetzee]

Must I change the second "1" in "0,1,1,0" to "0"?

[jasper_coetzee]

Must I change the second "1" in "0,1,1,0" to "0"?

[jasper_coetzee]

I did edit the facebookpixel database record, and it is now not enabled. But the site still gives the same message: "Error displaying the error page: Application Instantiation Error: Could not connect to MySQL."

So, something else must have gone wrong as well. I yesterday found a site that assists with that. I checked the site's configuration.php against the database record in cpanel for the four quantities:
public $host = 'your-database-host';
public $user = 'your-database-user-name';
public $password = 'your-database-user-password';
public $db = 'your-database';

All of that was fine. I even re-input the password per the configuration.php.

Now I don't know what.

[sozzled]

↑ Note the change of topic subject above.

Thank you, @jasper_coetzee, for your replies and informing us that:

1. you have succeeded in disabling the Official Facebook Pixel plugin that you installed—you will find the installation files in the folder ../plugins/system/officialfacebookpixel; and
2. installing this plugin has nothing to do with the database connection error.

My reason for the old Joomla version is simply that I did not think it matters that much.

If that were the case then there would be little activity on this forum! There's an old saying in our industry: if builders built buildings the way programmers write software then the first woodpecker that came along would destroy civilisation as we know it!

Having been in the IT industry for over 50 years, I know from experience that software unreliability grows exponentially longer over time. (By the same token, the software reliability does not necessarily improve when new versions are released!)

As I informed you in my previous post, there have been over 70 new versions of J! released since J! 3.4.3. At this point, however, that's a minor issue because the website is now dead. The site is dead not because of installing a plugin [that has been disavowed by the Joomla Extensions Directory]; the site is dead because the CMS is unable to connect to the database.

It's possible, but not without some technical skill, to point the CMS at the database—in theory you can point any J! website at any database—if you know

1. the SQL username and its password;
2. the host-name where the SQL database exists; and
3. the DB name; and
4. the DB table prefix used with that site.

These values are stored in plain text in the file ../configuration.php:

Code: Select all

.
.
.
	public $db = 'xxxxx';		// DB name
	public $dbprefix = 'xxxxx_';	// DB table prefix
.
.
.
	public $host = 'xxxxx';		// DB host-name (e.g. localhost)
.
.
.
	public $password = 'xxxxx';	// SQL user password (can be an empty string)
.
.
.
	public $user = 'xxxxx';		// SQL username (e.g. root)
.
.
.

These matters however do not address why you "did not get any result" when you tried to run the Forum Post Assistant:

I followed the advice of @Webdongle to download the Forum Post Assistant, but after installing the fpa-en.php and running it, I did not get any result. The feedback was "This page isn’t working; am-tech.co.za is currently unable to handle this request; HTTP ERROR 500.

The only thing that message tells us is that your website has some undiagnosed HTTP 500 Internal Server error. We may not be able to get to the bottom of the mystery if we can't see what the FPA report generates.

I also tried the method that the originator[of the topic viewtopic.php?t=971497https://forum.joo ... p?t=971497] used ... but with no result.

In that situation, the person who created that topic had installed a different product—also been disavowed by the JED—which, as it now turns out, was a bit of a red herring. Sure, the plugin is incompatible with J! 3.4.3 but it's not the cause of the database connection error.

The real problem is that the website is unable to connect to the database: this could be the result of changing the SQL username, its password, the SQL database host, the DB name, and/or the DB table prefix used with that site; this could be further compounded if the connection method is unsupported by the version of PHP used in this situation. This begs the question: what version of PHP is used by the website? (The FPA report, if it ran, would tell us that.)

It may help if you can run the FPA report against your working website (assuming the website that continues to work is located within the same hosting environment as the broken one). It won't help to see the FPA report for the working website if the broken one resides in a different hosting environment.

I can't advise you better without knowing more about the environment. Yes, there are lessons for us to learn from this case: (a) keep your websites updated; (b) don't install questionable software products; and (c) perform regular (i.e. once a month, at least) site inspections, audits and general maintenance ... and, especially, make backups that and store them off-site.

So, something else must have gone wrong as well.

Yup!

[jasper_coetzee]

Dear @sozzled,

I now rowed with this for some hours again. But, no luck. The database and the configuration.php settings are the same. I even tried some changes (completely changed the password on both sides, changed the host from '127.0.0.1' to 'localhost' and back), but nothing.

I now wrote the hosting company as follows:
"Hello Cybersmart,

I really went far with this issue over the last few days. Joomla Forum, etc. So, the original problem occurred after I installed the facebook-pixel plugin (the installation did nothing, but when I enabled it the website went blank). And then some time after that the "Could not connect to MySQL" error came up. Now, I disabled the plugin in the MySQL database, but the connection error persists. And everything in the configuration.php matches the actual database settings. I have now rowed with this issue for 3 days.

Now my question is: you do not perhaps have a recent backup of the server (newer than say 2 months) which you can restore?

Otherwise, I will probably have to find someone more savvy than me to try and sort this out. Or, alternatively, I will have to restore a backup made 18 months ago - that would be very sad indeed!"

I am not someone that gives up easily, but the logics of the sittuation says that there must be something else that causes the problem. I even now went and changed the name of the facebookpixel again. But, no luck.

I can tell you one thing. I will abide by your rules for site updates in future! I have learnt my lesson.

By the way, I developed the site based on a template bought from template monster. The original site, which I carried over to the company's host, is still up and running at https://www.m-tech-consult.co.za/joomla30/.

I want to thank you for all the trouble you have gone to in this process. I really appreciate it much more than you can imagine.

Regards,

Jasper

[leolam]

So let me just jump in with some ideas. You need to get rid o that plugin so here is what to do:

1) Delete the entire folder system/officialfacebookpixel
2) Go to the database and the extensions tables and delete the plugin with id "10123"
3) Check in the database if you have a menu item (menu table) to this plugin. If so "delete"
3) after these 3 are done click "repair database

This will completely uninstall the plugin and all it's files/folders and your issue should be resolved

Leo

[sozzled]

Although I agree with @leolam—about removing the Official Facebook Pixel plugin that you installed (disavowed by the Joomla Extensions Directory)—the "Application Instantantion Error" is probably unrelated to this plugin. It's probably a coincidence.

1. Your broken website was built with J! 3.4.3.
2. You have not told us which version of PHP you are using on the web space. If you are using PHP 7+ then you cannot run J! 3.4.3 (see Technical Requirements): footnote 1.
3. Even if you are able to restore your J! 3.4.3 website from a backup that was made by your webhosting provider, if you are using PHP 7+ you still will not be able to run it.
4. I suggested that you run the FPA tool with the working website. This may tell us what version of PHP it uses and, my inference, what version of PHP the broken website may be trying to use.

I think we can probably dismiss the activity of a plugin affecting the CMS's inability to connect to the database.

As a starting point, if you can't tell us what version of PHP you're using then we can't begin to explain why you're getting the cannot-connect-to-MySQL problem. That's what we need to know to begin with.

[jasper_coetzee]

Thank you @leolam and @sozzled,

Here is my newest. I am not making changes now, as I am presently out of options. I can do what @leolam suggests, but it seems as that will not solve the database connection issue as @sozzled states. I am now in the following position:
1. The web provider does not have a backup to help.
2. The site is using PHP 5.6
3. I have a person from India that eMailed me from the forum and offers to repair the site for $60. I have to provide him with my cPanel login detail. He is well reviewed on the following two sites:
1. [ redacted ]
2. [ redacted ]
If he could help me it would be wonderful. But to just give one's cPanel login is not my normal way of doing at all.

What advice do you have?

Regards,

Jasper

[sozzled]

1. The web provider does not have a backup to help.

That's not much help to you or anyone. I think the connection-to-the-database issue was coincidental to simply logging into your website for the first time in who-knows-how-long and something else has happened. As I mentioned earlier, there are five usual reasons why J! websites can't connect to the database:

1. the wrong SQL username and/or password;
2. the wrong host-name where the SQL database exists (e.g. localhost or somewhere else);
3. the wrong DB name;
4. the DB table prefix does not match with what's configured (in the file configuration.php); and/or
5. the webhosting environment—viz. PHP—doesn't allow the connection method (e.g are you using MySQL, MySQLi or some other mechanism).

2. The site is using PHP 5.6

That's good to know because J! 3.4.3 won't run on any version higher than that.

3. [A] person from India ... eMailed me from the forum and [offered] to repair the site for $60.

That's interesting because it's against the forum rules for people to solicit work—publicly or privately—through this forum. It's entirely your choice if you wish to take that person up on his offer. It's also interesting that you should post reviews about this person's reputation. I've seen cases in the past where people have referred to a forum user with a similar name who "cold-called" other forum users with similar "help". I'm just saying that one should be careful about accepting "offers" (especially if they involve a fee-for-service) from people you don't know or people who have not posted anything publicly in relation to the matter we are now discussing. There is a "professional services" forum where you can seek people to do things for you.

If [someone] could help me it would be wonderful.

I'm doing my best but without detailed information (viz. the Forum Post Assistant report) I can't do anything more than what I've done over the past 3-4 days.

First things first: you need to check that the details in the file configuration.php are correct. Ideally you should get the Forum Post Assistant to work. Failing those things, I don't know what else to advise.

It's your website and only you know if it's worth the effort of time and money to fix it. If nothing else, you've probably learnt few lessons: (a) make sure your web assets are backed up, and (b) maintain the website regularly and check for updates and information posted to you by your webhosting provider relating to plans that they may have that could jeopardise what you own.

[toivo]

I have a person from India that eMailed me from the forum and offers to repair the site

I've seen cases in the past where people have referred to a forum user with a similar name who "cold-called" other forum users with similar "help".

@sozzled is right, this forum should not be used for soliciting work. A member with a similar name was banned from the forum in 2019 because of repeated breaches of this rule.

[jasper_coetzee]

@ sozzled,

Thank you very much for all the trouble you went to. Thank you also for clarifying (with @toivo) about the forum rules (which I did not know), and also the link to the professional forum. I may even have to resort to that forum if I do not get this issue resolved.

I tried the Forum Post Assistant again, but it just gives a http error 500.

All the best,

Jasper

[sozzled]

I tried the Forum Post Assistant again, but it just gives a http error 500.

Then you have a hosting problem because the FPA software is a standalone product that's not actually part of the J! CMS. The FPA interrogates the target website's database, the hosting environment in which the website resides, and the website's filesystem but it's not actually a part of the CMS.

You can delve further into what may be the cause of the HTTP 500 server error by looking at the system log files. A good place to start is the file error_log located in the target site's root directory. It's a text file that you can download to your PC and open with any basic text editor (e.g. Windows Notepad). I would be contacting your webhosting provider to ask them for details about other sources of information (i.e. server logfiles) that you can look at.

Let's get the FPA to work first. We can then use that information to understand what's causing the "could not connect to MySQL" error.

One thing that I would try is temporarily rename the file .htaccess (assuming it exists) in the website's root directory to htaccess.old and then give the FPA another try. Did you double-check the SQL username/password (and other) settings in the file configuration.php? Are you absolutely sure that the information is correct?

As far as the user from India is concerned, as I wrote before, I've seen other people mention the same person elsewhere on the forum. That person seems to have a reputation for cold-calling forum users with offers of help. As @toivo also commented, a similarly-named user account was banned from the forum for the same reason—soliciting work.

[jasper_coetzee]

Hello @sozzled,

The guy in India solved my problem. I made a full backup of the site and sent it to him via Dropbox. He installed it on his localhost and told me to change the PHP Version, which was PHP 5.6 Native, to PHP 5.6. And the site is back!

So, now I will make a backup and then update all the software.

With best regards,

Jasper

[sozzled]

As I suspected, the PHP version was the source of the problem. I'm pleased that you got to the heart of the issue but I'm also quite irritated by this freelance developer's continued abuse of the forum in cold-calling forum users with "offers of help", without informing other forum users (like me and other volunteers who are either trying to help or who may be looking for a solution to their problems), and not contributing to forum discussions in public.

[Removed off topic section]

[jasper_coetzee]

Thank you @sozzled,

I learnt a few very important lessons in this process, and you were my coach:
1. Keep your site software updated.
2. Never mention somebody's name on this forum.
3. Solicitation is totally against the spirit of the forum.
4. This forum really works! Not all forums do.

Another thing: Joomla is an awesome CMS. And it attracts awesome people like yourself.

Thank you again,
Jasper

[sozzled]

Thanks, mate. Please add to your list a "number 5"

5. Make use of the Forum Post Assistant tool!