It happended to me just after installing the latest version. I am not sure, though, if these strange characters were already in the file before. It was an ini-file, and the corresponding program just ignores such lines, so I can't say for sure how long they have alresdy been there.
It may be an issue that only happens when editing several files side by side. The reason I think this is the case is because this inserted text contained, embedded in the garbage, some short segments of text that obviously came from another file that I often edit in parallel. -- <https://forum.pspad.com/read.php?2,75435,76030> PSPad freeware editor https://www.pspad.com