Thanks Myra! I just got this email back from the IT group:
Hi Mimi,
I mention that I used the wordpress themes developed by wordpress because they also suggested that some themes can cause issues as well, so I wanted to remove our CALS theme as a possible culprit as to why their plugin was not working—thus even using it with different themes it still causes the error.
Your question actually prompted a new line of inquiry for me on “what has changed”. Back in November 2022 we completed (along with DoIT) a major upgrade to PHP version 8, which is the underlying language that WordPress runs on. This was a necessary upgrade for performance and security.
During our pre-upgrade testing we had a number of third-party plugins that caused critical site errors that needed to be fixed by their developers. Fortunately most developers were aware of this major update to PHP 8, and they updated their plugins if they had issues with PHP 8 errors, some plugins that were abandoned did not, and the plugins had to be removed from our system. Anyway, This got me thinking that perhaps the in5 plugin was actually incompatible with PHP 8, but just not throwing a typically site critical error.
On my local test wordpress I have the ability to roll back the version of PHP to version 7.x, and my hunch was confirmed. The plugin worked and uploaded the file when I rolled back the PHP version. So I can fairly certainly confirm that the plugin is likely having an issue with PHP version 8. The reason we didn’t notice at first is the way it is throwing the critical error. Typically the plugin will not even activate or run, and will completely bring down a site. But this one was only causing a critical error on upload.
Anyway, I’m fairly confident that is what is causing the issue, having tested it several times toggling PHP version back and forth. To get this fixed, I would alert the plugin developer that it appears there plugin upload is not working on PHP 8 and hopefully they will push a fix that we can then update on our wordpress platform.
Best,
~Mark
Mark Millard
Web Services Developer
CALS IT, College of Agricultural and Life Sciences (CALS)
mark.millard@wisc.edu
(he/him)