Unable to login to Plesk: login page hangs or shows ERR_CONNECTIONS_RESET

Symptoms

Unable to login to Plesk: no errors appear, the page just loading endlessly.

The following error may appear in a browser while waiting for a page to load:

CONFIG_TEXT: ERR_CONNECTIONS_RESET

Cause

This is Plesk bug with ID PPPM-7137 which is planned to be fixed in future product updates.

Resolution

As a workaround:

1. Connect to the server using RDP .
2. Open Plesk Services Monitor and press Stop Plesk website :
   
3. In Task Manager terminate all the php-cgi.exe processes owned by psaadm user, because they can lock php_lock_manager.dll file

   

4. Download the custom fix attached and unpack it.
5. Replace %plesk_dir%\admin\engine\php_lock_manager.dll with extracted custom fix file.
6. Open Plesk Services Monitor and press Start Plesk website

If the patched php_lock_manager.dll does not fix the issue, it is possible to disable lock_manager in Plesk php.ini file:

1. Connect to the server using RDP.
2. Browse to "%plesk_dir%\admin\conf\" directory and open php.ini with preferable text editor
3. Comment the following lines by adding a semicolon at the beginning of the line:

   CONFIG_TEXT: ;[php_lock_manager]
   ;extension=php_lock_manager.dll

4. If the issue still persists, restart IIS in CMD:

   C:> iisreset