Editor windows randomly stops working

We’re having an issue in our team where various windows in our editors stop working, more or less at random. The problems started Friday afternoon and at first we thought it was down to a specific commit to our source control, which had introduced the errors. However, some people who were up-to-date did not have the errors and those who had the errors didn’t necessarily see all the problems. So eventually we all updated to the latest revision, which results in most of us having the errors, but not all of us.

To give an overview of what’s happening, here’s a list of the errors we’ve seen since this weirdness was introduced on Friday:

  • Blueprint Editor is completely blank. The top menu is there (the one with File, Edit, etc.) as well as the parent class reference and search field, but everything else is blank.
  • Content Browser is completely blank. The “Add New”, “Import”, etc. is there, but everything else is blank. Interestingly, if choosing Content Browser 2, 3 or 4 those will work.
  • Rotating the camera in the viewport is impossible. This was due to the mouse sensitive being set to 0 for some reason.

As said, it’s not everyone who gets these errors and they rarely all happen at once. After a period of debugging and internet searching we found a couple of methods that may fix the issue(s). These are:

  • Delete the Saved folder in the project library.
  • Delete the DefaultEditor.ini file from the Config folder.
  • Reset the layout from Window->Reset Layout.

It’s not given which of these fixes will work, but so far we’ve found that at least one of them will. The problem is that the issues will eventually return, which means we have to go through the fixes once more. It’s taking away quite a significant amount of time that we have to do this every once in a while and since our layouts get reset every time it happens, people can’t work with their preferred layouts for the editor. As said, the errors seem to come more or less at random, or at least we haven’t been able to figure out any consistent way of reproducing the issues. It seems that there might be a correlation between changing our layouts and getting the error(s), but it hasn’t been proved…

We’re running the Unreal Editor 4.13.1.