This is still an issue in Xcode 14.1 (14B47b), at least for \u{2011} (Non-Breaking Hyphen) which gives: invalid unicode sequence: \u{201

I run into this today, too. 3 out of 7 of my screenshots failed. Consistently and always the same three. I tried renaming the file and exporting it as a PNG without the alpha channel, but it didn't work. What worked was going out of the "Media Manager" page re-uploading only one of the "invalid" screenshots. When I went back to the home page for the app, the screenshot didn't show the IMAGE_TOOL_FAILURE error. I repeated the process for the other two, again by uploading only one via Media Manager and then going out of that page, and it worked. Go figure...