Here's the docs about Tokens, very helpful to set up generic paths, automatically adapting to project parameters. But if you don't know about them, they will not have been the culprit.
I guess, we will not be able to solve this, as the erroneous settings are gone.
Another possible cause of the issue not mentioned in here, yet: Maybe some special character not allowed in the filesystem crept into the erroneous path. Anyway, we will never know.