Do you experience problems during downloading?
Check your connection in Status and Interface settings window.
Use Test Server in Config > Servers.
We will probably ask you to do a test using only basic settings.
Do you experience problems during repair or unpacking?
Enable +Debug logging in the Status and Interface settings window and share the relevant parts of the log here using [ code ] sections.
It's quite simple. CouchPotato sends error messages to SABnzbd as if they were NZB files.
CouchPotato should be dealing with errors from the indexer by itself and not send garbage to SABnzbd.