SE goes into a loop when loading the "b1.properties" file in the attached project. I concede that the file is not proper properties file format, but SE should not go into the weeds like that. In fact, it may not even be relevant to the problem.
I ran into this bug while diffing 2 UTF8 files using a named diff config, and the diff sent SE into a CPU loop every other time I ran the diff. It turns out that the named diff doesn't save the line/source mode toggle, and the loop occurred when source mode happened to be active after loading the named diff After lots of bisecting, I ended up with the 2 one-line files in the project, b2 loads, b1 doesn't.