--- Sharepoint 2013. Vers.15.0.5285.1000 (On-premise) ----
Recently all of my content sources, got the following error. Leaving around 80% of the items in the index, error-prone and unsearchable.
The item could not be indexed successfully because the item failed in the indexing subsystem. ( The item could not be indexed successfully because the item failed in the indexing subsystem.; Content group cancelled by generation controller; Aborting insert of item in Link Database because it was not inserted to the Search Index.; ; SearchID = 6E4BF12E-19E3-4C8B-9441-F6D8E66B3786 )
Searching around the internet I've found examples of many similar, but not identical errors. Specifically 'Content group cancelled by generation controller' is where the error differs from most documented instances.
I've tried the following:
SP Cache Reset on each machine in the farm
Restarting each machine in the farm
Recreating the entirely new SSA, on a entirely different machine in the farm, and crawling from scratch
SharePoint Configuration Wizard on the crawling machine
Change the crawling target to another machine in the farm using the hosts file.
All the machines involved have a large surplus of space on all their disks.
Have anyone experienced something similar? And if so, was it solvable