When I tried editing 2019 Abqaiq–Khurais attack today the Visual Editor gives me a "HTTP 404" error when I try and save.
I did a wide array of edits, including Wikilinking, text editing, text additions, and Infobox editing using TemplateData. It would be difficult to replicate the exact edits I did but I cannot think of a culprit. Possibly abuse filters, or edit conflict, or something of that sort? As this is not occuring on any other pages I edit.
Screenshot of the error:
Luckily, I can reload the page and my edits are recovered but I am unable to publish the changes I have made. I cannot switch to source editing either. Screenshot of switching:
Browser: Google Chrome Version 76.0.3809.132 (Official Build) (64-bit)
OS: macOS 10.14.6 (18G95)