Hi.
I did rollback to Helix Ultimate 1.1.4 and SP page builder 3.7.13 (for my public websites). The page error works fine (but it worked fine also with Helix 2.0.4 and SP page builder 3.7.13).
I tested on local website the updating to SP page builder 3.7.14, with Helix Ultimate 1.1.4.
I have the same problem: it seems to me that the error page is not loaded. (The html code inside the page is different, it's not the usual code for basic error page).
So, I think that there is a problem with SP page builder 3.7.14... And so I can't update to it! :(
Please fix it or tell me how to temporarily fix it!
For other examples, trying yesterday and today on your website...
The problem is similar to this:
https://www.joomshaper.com/forumjj
The correct page error works fine here:
https://www.joomshaper.com/blog/ciao