Modal not found Error 500 - Can't edit/create articles and categories Topic is solved

[marcz99]

Hello!

After migrating from J3.10.11 to J4.2.6, the front end seems to be fine but I can't edit an existing article or write a new article and it's the same with categories from the backend. I get the following error message "500 behavior::modal not found". I managed to add new modules on the site but I'm stuck with not being able to edit content or write new content - articles and categories.
I tried editing an article from the front end and I get this same 500 error and modal not found. There is also this line "Warning: Undefined property: stdClass::$catslug in /home/ucatwckp/public_html/templates/j51_skylar/html/layouts/joomla/content/info_block/category.ph"
Thank you for your help.
Marc Z

[pe7er]

Welcome to Joomla forum!

Your template is not compatible with Joomla 4. Try switching to the default Joomla 4 template "Cassiopeia"

You probably have some system and content plugins that are not compatible with Joomla 4.
Try to switch those off (use FTP to rename their folder so they are not loaded, or switch them off in the #__extensions table using phpMyAdmin)

[marcz99]

Hi pe7er.

Thanks for your reply. The template is Joomla 4 compatible, I bought it on Jooma51 and I tested it on a test website. I tried switching to Cassiopeia but it doesn't solve the problem.
First, do I have to disable every plugin one after the other and then see if it solves the problem? I'm not sure if I'll know where to go to rename the different folders. Is that done in the "plugins folder" in FTP?

Thanks again for your help.
Best regards.
Marc Z

[pe7er]

First, do I have to disable every plugin one after the other and then see if it solves the problem? I'm not sure if I'll know where to go to rename the different folders. Is that done in the "plugins folder" in FTP?

If you switch on Joomla's debug mode then it will display a stack trace that might be helpful in finding the faulty plugins.
In configuration.php change:
public $debug = false;
to
public $debug = true;
to enable the debug mode.

Disable the plugins one-by-one (start with the faulty ones that you see in the stack trace)
and only the 3rd party plugins of type System and Content.

Use FTP to rename the specific plugin folder.
For example, if you would like to disable Joomla's default Email Cloaking plugin, rename
/plugins/content/emailcloak
to
/plugins/content/emailcloak-old
and Joomla won't load it anymore.

[marcz99]

Hi again!

I disabled the plugin called "Button - Creative slider" which I haven't used in ages and that did it. Problem solved apparently. I can now edit articles and create new ones.
There is still the line in the front end that says, "Warning: Undefined property: stdClass::$catslug in /home/ucatwckp/public_html/templates/j51_skylar/html/layouts/joomla/content/info_block/category.php on line 18" but it doesn't prevent me from editing and writing articles.
Thank you so much for your help.

I guess this entry can be marked as "SOLVED".

Thanks again.
Best regards.
Marc Z

[toivo]

Thank you for the update!

templates/j51_skylar/html/layouts/joomla/content/info_block/category.php

This file belongs to a template override, stored in the html folder of the template. The developer may not have updated the PHP code to be compatible with the latest versions of Joomla 4.2. You could rename the file category.php to category-old.php to see if that gets rid of the issue and that nothing else breaks. Alternatively, change Error Reporting in Global Configuration to 'None', which is the recommended setting for live production sites.

[marcz99]

Thank you so much for your detailed replies and for being so prompt in helping out.
Problem SOLVED then.
Best regards.
Marc Z

[mercury]

Final comment on Marc Z's problem .... had an identical situation with a recently uploaded J4 live site. No problem on localhost but required your solution above to the same plugin to access articles etc. Appreciate the input!
Also recently had an interesting problem with another image extension when attempting to set up plugin parameters. Wouldn't save in Firefox but did save in MS Edge. The saved changes later functioned without a problem on the FF browser. Cheers ... Rod