Stop 500 status pages on the admin panel

No idea why, but we are getting lots of 500 internal server errors on our admin page when our staff try to submit new entries or when I update snippets or do most things that use forms.

The form seems to take ages to submit, then goes to the 500 page. The strange thing is that it does actually go through but the error page is unwelcome. Nothing seems to have changed on the back end, the 500 error pages are just appearing a lot now.

Also our admin page (which is normally super fast) seems to be taking a 3-4 seconds to load as opposed to less than a second which it normally takes.