Unable to login to Joomla 5 backend

[dagroupinc]

We've been having this same issue with one of our Joomla 5 sites. We've tried the above solutions (htaccess, php, config) and still can't get the admin log in to work. Any other thoughts? Here is a comment from Siteground:

"I have checked your case again and the issue appears to be coming from a JavaScript code for the login button not working as intended with the following error getting recorded when clicking on it:"

Uncaught TypeError: e.submitbutton is not a function
https://{ourwebsite}/media/mod_login/js/admin-login.min.js?d6fedc:4

Our inspector shows:

Uncaught ReferenceError: jQuery is not defined
at jquery-noconflict.min.js?504da4:1:7


ADDITIONAL INFORMATION:

We have been able to successfully log in as admin by restoring the site from a backup copy. What's interesting is that we haven't made and changes of any kind to the site.

Anyone with thoughts?

[toivo]

Which version of Joomla 5 was the website using when the error occurred? What is the Joomla 5 version after the site was restored?

Our inspector shows:

Uncaught ReferenceError: jQuery is not defined
at jquery-noconflict.min.js?504da4:1:7

This error must be coming from a third party extension because the backend login page of an out-of-the-box Joomla 5.2.3 does not use jQuery.

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

[dagroupinc]

Well I've been trying to generate the report but I can't get the script to run. First issue was a 403 error, then when I finally got past that I get a 'timed out' message. I deleted the script, cleared the cache, uploaded another new script and keep getting the 'timed out' message:

As a security measure, this copy of FPA has been self-deleted due to the time it has been present on the server.
You will need to upload another copy of FPA to continue.

Not sure why it doesnt recognize that I have uploaded a new script. I just keep getting the message.

[Per Yngve Berg]

Not sure why it doesnt recognize that I have uploaded a new script. I just keep getting the message.

Your FTP App has an Option set incorrectly. The original time of the uploaded file is retained. Good for backups, but in this case it must be set to the current time.

[dagroupinc]

i made sure it's set for the current time but still get the same message