It looks like there might be a rogue folder on the Chorus Hub server that is causing problems.
Shamelessly quoting @John+Wickberg from another user that was having this same problem:
My guess is that there is some extra folder in the C:\ChorusHub directory of the machine that is Chorus Hub.
If you look at the C:\ChorusHub folder, Paratext projects should be subfolders with names like:
ABC^P8586e599199828055be414d6a13c207751d6d4cb8
ABC is the short name of the project, ^P8 is a separtor, and what follows is the internal id of the project - which should be a 40 character string.
Any other folder that doesn’t match this format may be the problem.
EDIT: For a little clarification, the folder causing the problem will have “^P8” in it, but will probably not have the following 40 character string.