Dashboard "Recent Courses" and some sidebar links don't work after upgrade

Re: Dashboard "Recent Courses" and some sidebar links don't work after upgrade

by David White -
Number of replies: 0
Thanks for the SOS.
The /admin/ portal works perfectly fine, thankfully. It's just the link that is supposed to TAKE me to the admin portal that is broken.
I can type /admin/ in the URL, and it will get me there.

I did try clearing all of the caches, and unfortunately that doesn't resolve the issue with the links.
The links in the sidebar are what I'm referring to. See the screenshot below.

So in this view, when I click on "Courses", I see this wheel sort of spinning - you can see it in the screenshot - and the Courses doesn't expand downwards.
The same is true for whenever I click on "Site Administration".

Navigation sidebar


This feels like some sort of AJAX issue, as opposed to a php issue. 
I do have a php_errors.log file that I'm logging PHP errors to, and definitely don't see any relevant errors (or any errors, for that matter).

I did turn debugging on briefly earlier this evening, and this error does look interesting to me.
I don't think its relevant, but it caught my eye:

[08-May-2021 18:59:57 America/New_York] Default exception handler: Sorry, the requested file could not be found Debug: 
Error code: filenotfound
* line 498 of /lib/setuplib.php: moodle_exception thrown
* line 2075 of /lib/filelib.php: call to print_error()
* line 4990 of /lib/filelib.php: call to send_file_not_found()
* line 44 of /pluginfile.php: call to file_pluginfile()