Tor browser download error version 6.5a3 hardened in whonix with updated developers repositories.
Don’t use the developers repository at this stage. However, as the developers repository is the same as the testers repository currently, no harm done.
Your issue description is too unspecific to be able to debug it. What’s the error message?
Alternativly it’s alwayws possible to skip tb-updater and do it manually.