I sorta suspected there was another issue, as I tried backups from August... and it still did not work.
So, if the issue is no longer a bad database, do you have any idea on what steps I should try next?
Also, do you know of any instructions on how to setup ceton with version 6?
I would like to be on a supported version if possible...
There is no migration path but I believe it would be possible yes based on what I saw. As a minimum NextTool can import any video file even files not recorded by NextPVR. My suggestion would be to install v6 in parallel and change the web port for v4 to 8867 and work on the tuners first. Guide and recordings come later.
If it was me, I'd bite the bullet lose a tuner and spend the $150 for a Prime or more likely buy some used DCR 2650s on ebay or kijiji since Cable Card's future is not guaranteed.