I don't see what the problem was. The icons worked fine for me and easily displayed the file type on them.
Now they just show 321 regardless of file type.
I don't really think they were that easy to read, but I do kind of understand where you come from. I didn't really pay much attention to them, so although they were not exactly pretty or readable, I didn't do anything about them. Then came Lord's scrutiny, and we have what we have now, since he did have a point in his comments. In the end I wasn't really even reading the text on the icons, so I couldn't even really fight against his review (text on icons is a problematic thing to begin with since they're supposed to be "visual" representations or whatever the correct term is).
Anyways, I know and acknowledge that the current result is not optimal, and I can also understand that some people might or might not be way too used to the old way of things, which is I have posted the mpciconlib binary that was originally going to be added to the release a few posts upwards from yours, and if you need it you can get it. You can then extract it into the folder where MPC-HC resides and handle the extensions you need from there, from its options.
I'm uninstalling and going back to the last release. If future releases continue to take a step in the wrong direction I'll probably have to resort to switching to something else like K-LITE.
Yes, ignore the actual positive technical points and results, and completely keep to a relatively minor visual problem that you can relatively easily deal with as I have written

I'm quite happy (not!) that this seems to be a bigger problem than the fact that I seemingly forgot to commit a fix to a copypasta error in my custom code to MPC-HC. Of course, the bug is in no way lethal, doesn't affect people using the defaults, and doesn't even stop people from using the related features, but you have no idea how long I facepalmed after finding out that even after fixing it once and most probably even making a build or builds with it, it was lost somewhere in between the last stable and this release

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