I have a text file that is created as trace log output from my application. I often open this in VS to look at the traces. The files are NOT part of my solution.
I used to do some easy visual filtering by doing a find for a keyword. The "Highlight find results" option would conveniently color all trace lines that had that keyword making them easy to see. I have recently noticed that this stopped working for these text files. Highlight find results is still working fine in the regular source files. I haven't determined the direct cause yet. I'm not sure if being part of the solution or not is an aspect of the problem.