As @JonMikelV suggested to me in another thread while troubleshooting this issue myself, try entering the following advanced option while on the “encryption” step of the Restore job setup:
–no-backend-verification=true
When I tried running it this way, the restore operation still threw the same error message regarding the “missing” dblock files, however instead of stopping there, it proceeded to perform the restore operation and successfully restored the test files I was attempting to restore. The reasoning is, I believe, the “missing” files are identified in outdated index files but no longer actually needed.
Please try this method when you have a chance, and let us know if it seemed to work for you.