I think the "No Database Connected" warning should be dealt with first. Look up Solution S-020198 in the KB. I could copy/paste all of the info here, but it would be long. Basically, it sounds like you have an orphaned Vault View with some registry info possibly missing. The Solution has detailed info to troubleshoot it.
That would also be inline with not being able to check out and write to the vault when you are using Acrobat.