Hmm, that is very bad.
How big are these files (roughly)?
The crypt format is broken up into 64k chunks and I have a version of rclone which will write zeroes for the chunks with errors, but otherwise carry on, so we could investigate how much of the file is corrupted if you want.
If it is something like a video file then a 64k chunk lost will cause a minor visual artifact. If it is something less resilient then a 64k chunk missing might make the whole file useless.
Good news on the retries.
I look forward to the final score!