Media browser thumbnails not showing after upgrade from 2.8.4 to 3.0.4

Two sites running 2.8.4 MODX. Both initially PHP 7.4. One I can upgrade to PHP 8.1, then upgrade MODX to 3.0.4 and all is fine. The other has software that needs PHP to remain 7.4, so I add the extra dependencies that I know about and upgrade MODX to 3.0.4. All seems okay until I look at the image template variables and the media browser. There are no thumbnails. Images on the front end show normally. There is nothing in the error log relating to images or thumbs.

I found a mention of a media thumbnail bug in an earlier version of MODX said to have been fixed. Is this a reappearance of that bug or is it due to PHP dependency that I don’t know about? Do I need to revert to 2.8.4 to get the thumbnails back?

For want of a better idea, I installed 3.0.3 to take it down a notch from 3.0.4, which it was running, and that brings the thumbnails back. Coincidence? Will stick with that for the time being.

It’s a known issue with MODX 3.0.4 and PHP 7.4.
Take a look at this topic:


My bad for not finding that thread, where you very kindly explain it all.

It helps massively just to know there is an actual problem, and it is not just me breaking things again.

Thank you for the assistance.

I thought there was something here to click to mark your answer as the solution. Perhaps it is the cataracts again, but I don’t see it.