Joomla Administrator Page error

[Narhari]

Hello to the Joomla Team,

I am trying to access the Joomla website but when typing in my website's url/administrator, I can see the error message on the screen:

This page isn’t working
...website domain... is currently unable to handle this request.
HTTP ERROR 500

I am using Google Chrome.

Receive the error on all the browsers.

Appreciate your urgent help to fix the admin login screen so I can fill in the login details and login into the dashboard.

Thank you.

[sat2021]

Hello to the Joomla Team,

I am trying to access the Joomla website but when typing in my website's url/administrator, I can see the error message on the screen:

This page isn’t working
...website domain... is currently unable to handle this request.
HTTP ERROR 500

I am using Google Chrome.

Receive the error on all the browsers.

Appreciate your urgent help to fix the admin login screen so I can fill in the login details and login into the dashboard.

Thank you.

There must be some fatal error.
you have to edit configuration.php and change error_reporting variable value from default to development.
Then it will show exact error.

[Narhari]

Upon changing the error_reporting variable value from default to development, the following errors were displayed in the administrator login page:

Warning: strstr() expects parameter 1 to be string, object given in /home/********/public_html/********/libraries/joomla/cache/controller/callback.php on line 63

Warning: strstr() expects parameter 1 to be string, object given in /home/********/public_html/********/libraries/joomla/cache/controller/callback.php on line 69

Fatal error: Call to undefined method JApplicationAdministrator::isClient() in /home/********/public_html/********/administrator/components/com_login/models/login.php on line 146

Line 146 displays:
if ($app->isClient('site') && $app->getLanguageFilter())

// Filter by language.
if ($app->isClient('site') && $app->getLanguageFilter())
{
$query->where('m.language IN (' . $db->quote($lang) . ',' . $db->quote('*') . ')');
}

[toivo]

The topic was moved from Joomla 4.x to Joomla 3.x because the error messages indicate that this is a broken Joomla 3.x site.

Is this a newly installed site or have you tried to update an existing site?

Please post the results from the Forum Post Assistant (FPA) by following the instructions at https://forumpostassistant.github.io/docs/ so that the configuration can be reviewed.

[Webdongle]

How was it installed?

[sat2021]

Upon changing the error_reporting variable value from default to development, the following errors were displayed in the administrator login page:

Warning: strstr() expects parameter 1 to be string, object given in /home/********/public_html/********/libraries/joomla/cache/controller/callback.php on line 63

Warning: strstr() expects parameter 1 to be string, object given in /home/********/public_html/********/libraries/joomla/cache/controller/callback.php on line 69

Fatal error: Call to undefined method JApplicationAdministrator::isClient() in /home/********/public_html/********/administrator/components/com_login/models/login.php on line 146

Line 146 displays:
if ($app->isClient('site') && $app->getLanguageFilter())

// Filter by language.
if ($app->isClient('site') && $app->getLanguageFilter())
{
$query->where('m.language IN (' . $db->quote($lang) . ',' . $db->quote('*') . ')');
}

there seems some old version files.
you may tried to update joomla and it was not successful completion.
you need to replace libraries folder.