Your E: drive is not working. What is it? Is that Mountain Duck mounting Storj S3 as drive letter? That’s all outside of Duplicati, but you can test by hand running as the same user Duplicati uses.
I think a Command Prompt dir accepts \\?\E:\ syntax, but Explorer might also be suitable test.
About → System info → UserName will tell you Duplicati’s user if you’re not certain. You can also see whether Duplicati Source screen can get there. If it can’t, then backup probably cannot either.
How is the Destination going to Storj? I can’t advise if Canary will help without you telling me that, however that might not matter now because the problem of the moment looks like broken Source which is technically out of scope for Duplicati to solve, although there’s a chance advice can help.