Original Kickstarter MOD Duo, can't upgrade - File corrupted

Hi, I have an original Kickstarter MOD Duo which I’ve never upgraded. If I go to System, its value is fbbfb5f. Not sure if there is any other information that would be useful to give. I can reach the Pedalboard UI but I think it is before the built-in auto update functionality there. I’ve tried upgrading it via the Releases page on the wiki, but no matter what I always get File Corrupted when I put the tar file on the MODDUO device drive. Here’s the kicker though, I looked at the other threads that point out how the upgrade system changed and how this tar file will work with anything: Release 1.0.0 (Release Candidate #1) however not even this tar works for me. I still get file corrupted. I think I might need some assistance?