When I have the views plugin active I get an http 500 error on all pages and cannot edit any posts or pages. When I deactivate the plugin everything is fine again, but then I don't have access to content templates.
Then, check if the issue also persists with a WordPress Default Theme and NO Plugins BUT the Toolset Plugins?
If not, could you then re-enable the Plugins one after the other, and check the issue each time you enable a plugin?
Please report me when the issue comes back
It might also be due to the Theme.
Please do reactivate your Theme only after you are sure the issue isn't coming from a 3rd Party Plugin.
If after all these steps the issue persists, again let us know the PHP error that will show after you enable WP Debug and eventually attach a copy of your site: https://toolset.com/faq/provide-supporters-copy-site/
The errors all refer to other plugins and themes.
These will appear as well if you deactivate Toolset.
I deactivated all plugins except toolset plugins. This resulted in a working site so I left Divi installed
This means the issue is not in Toolset.
It seems to me this issue will as well happen if you just remove Toolset from your site.
If this is ONLY happening when you activate Toolset, please add a Site's Snapshot, as this would then be a complex compatibility issue and not a replicable BUG.
We wouöd then need to contact the authors of those plugins to work with them on solutions.