I have had a Joomla! website installed on Joomla 3.9.4 with a template called "J51 - Artisan". I've successfully updated all the way to 3.9.4 since 2015, but recently tried out the update to Joomla! 4 Beta with a 500 server error.
When I investigate, by changing error reporting to "maximum", I get the following information on the homepage.
I also get these:
I tried to figure out what it could be that is causing the problem, and two pieces of evidence seem to stand out - firstly that there is a problem with jsnframework (which I note is causing problems for other peoples' updating of Joomla!), and secondly that the main template itself could be the problem (as this thread seems to point to templates that are incompatible with Joomla! v4 https://github.com/joomla/joomla-cms/issues/24642).
For now, I have rolled back the changes to this morning's backup, but I would like to try updating again if possible.
Any help with what the cause seems to be would be greatly appreciated.
All the best,
Pádraig
