Hi @support-huge-it,
I encountered the same error with 2.3.1 on 4.7.3. The site was running fine, but at some point started to return 500. Back then I didn’t have time to debug it and it got back normal. Today, a few weeks after the first incident, I figured out the Call to undefined function portfolio_gallery_isset_table_column() is the problem. The weird thing is that now and a few weeks ago, everything fixed itself, I didn’t change anything. It just doesn’t work every now and then with no apparent reason.
I’m happy to provide you with more info required to fix it.
