Problem: Bandlab Assistant, when downloading a project from BandLab for Cakewalk, when creating the target directory, tries to use the exact project title as the directory name. When that project title contains certain characters that are forbidden in Windows file system names (for example, one of: : / * ? \ ) it fails.
In my case, the project name is: "Cover: (bla bla)". So, the ':' character is the cause here. The error message is very vague: it does not tell what is wrong, but only: 'Download Stems' 'Export Tracks Fail' 'Something went wrong'. Also, it displays wrong feedback: it says has succeeded ("Stems saved in the BnadLab Assistant directory" (yes a typo: it says BnadLab not BandLab)) while it has failed. Only when clicking the 'View Folder' button, the user gets some info: a new error message says "Windows cannot find '(path of the directory)\Cover: (bla bla)'". And then, if you have enough expertise, you can see that a directory name with a ':' cannot exist in Windows.
I think the following fixes should be made inside BandLab Assistant (being a software developer myself):
Don't try to use the exact project as name for directories or files. At the very least, replace illegal characters by underscores or so. But also limit the length of the names, else you get different problems.
When something goes wrong, display all error information details you have. In this case: 'could not create directory '(path of the directory)'.
Display the feedback after the result of the action is known, not before. So that if the action fails, you don't display misleading 'Stems saved in directory' but you display correct info, e.g. 'Downloading of the stems failed'.
Hint to the developers: please note that there's another issue, not related but imo equally severe, with the downloading of projects by BandLab Assistant: empty wav files (search in this forum for; DirectShow error [0x80040265]). If BandLab Assistant is to be the transport pipe between BandLab and Cakewalk, better make it robust.