Symptoms
Host Server logs are filled with errors of this format:
Process instance [ProcInstID] not found for [user]
Diagnoses
The ProcInstID appearing has either been completed or does not exist at all (ServerLog.ProcInst, Server.ProcInst)
Resolution
1. Stopped the K2 blackpearl service
2. Made a backup of the K2 database
3. Ran the [ServerLog].[lProcInstRemove] stored procedure and provided the ProcInstID appearing on the logs
4. Started the K2 blackpearl service