Hi @alamos54 and welcome to the forum. I’m sorry about the dblock, but I’ll try some suggestions. This isn’t something I’m expert in, so I’ll partly be pointing to things that the experts said, and hope that those help you.
Lost dblock files are generally not considered recoverable. They backup source file blocks to the destination, however It’s not clear from you whether this is failing repeatedly, or just once (at which point you stop to ask).
Having a file come down bad would be one thing. Having it get bad on the backend would be another. Please save copies of all files if it’s not too late already, and consider saving the job database which is where info on what to expect is saved. The job’s database location can be found on the job’s Commandline page in dbpath.
That page might also help if you usually use the web UI, because you can adapt it to run your new command.
The AFFECTED command can show source file impacts of losing that file. There is also a Disaster Recovery article where one dblock file is intentionally corrupted, and another intentionally deleted. This is then cleaned.
That might be a good guide for you, however sometimes the consistency checking looks at file presence, not corruption (a full scan for corrupted backend files would currently require downloading all of them), therefore there is a chance you might have to manually change a dblock file corruption into deletion of the backend file.
Here is a post by the expert that gives me further confidence that a delete (if necessary) and purge-broken-files may help, if it actually comes to that point. I’m wondering if you’re up for runnng file hash checks or binary comparisons.
If you’re technically inclined, there’s more that could be done to gain a better understanding of this rare issue. Regardless, it would be helpful to hear about your environment, e.g. the Duplicati version and the destination.