In my app, I'm still running 3.6.4 because I'd had some issues with the 4.* versions. I'm working on testing 4.1.1 to see how it goes, and so far so good - except for one issue.
When tapping the "Source" button to edit the content source code, at first it shows up in the normal Courier-looking typeface - but click inside the window to position the cursor and the source code text changes typeface to Arial (or a similar sans-serif font).
Not a major issue, it doesn't affect the editing of the code itself - but it's weird and I don't like it, and don't feel like i can put this out for client use in this state.
I tried the demo on the cksource site to see if it was doing the same thing - nope. I suspect it's some holdover code on my end that doesn't affect the 3.6.4 version in that way, but I've yet to track down what it is. I've been commenting out various bits and pieces and no joy yet.
Any ideas what might be causing this? Might help me puzzle out where in my own codebase to look for the source (pun intended) of this issue.
Edit: Worked it out. It was an old style affecting textareas in my CSS that never affected the 3.* CKEditor versions.