You shouldn t worry about the bot The bug is apparently only for images with unusual characters such as accents You can just avoid them for now Or just delete the message from your talk page and mark the faulty page for speedy deletion this criterion seems to fit I believe you can also request white listing at the talk page though I wouldn t bother One other thing is that if it notices that there is no rationale it will inform you because you were the last one to upload a new version What I have done so far is to just copy the warning over to the talk page of the original uploader if it looks like they are still active Otherwise I just add whatever seems appropriate I generally won t rescale an image I feel has no place so most times I don t have a big problem with adding rationales But as I said if the original uploader is present it is their problem As for what should be in a rationale well it should generally point out how these criteria are met If the standard template is filled out you re generally well covered I ve started writing up the most common stuff I encounter Also feel free to dig through my contributions and look for edits with the summary Fair use rationale added for further inspiration