I would like to report that the problem still occurs, I have seen it for years. For example, while trying to upload this file, I get a very similar situation to the case of the description here in this thread (instead of exclamation mark there is a red X, and instead of "filename toolong" it says: "filenames can't be longer than 240 characters" (I use Hebrew on Commons, maybe the wording is slightly different in English originally) and it doesn't let me to move ahead to the next stage, where I can change the filename for the Commons version to an appropriate form.