May I know whether it is possible that there is only history opened incidents for an active process instance?
In fact, I faced the very strange case. The state of a process instance is ACTIVE, and there is an incident in ACT_HI_INCIDENT table related to the process instance, the incident_state_ of which is 0. However, there is no related record in the ACT_RU_INCIDENT for the same incident. I wonder whether it is a normal case or just something wrong with the engine.
Incident gets created in both history and runtime-related tables. Once the incident gets resolved, it gets removed from the runtime-related table " ACT_RU_INCIDENT" so I believe that the incident is already resolved in your case.
Incident_state_ is 0 is what is confusing me. Since what I know is that
a. 0 mean Incident Opened
b. 1 mean incident resolved
c. 2 mean incident deleted
So if state of incident is 0 therefore there must be a incident in ACT_RU_INCIDENT table.
I can think of a possibility where you are getting dirty read of ACT_HI_INCIDENT table. since the moment any incident happen there will entry in both the table i.e. ACT_RU_INCIDENT and also in ACT_HI_INCIDENT. Then when you resolve this incident then record will be deleted from ACT_RU_INCIDENT table and incident_state_ will be updated to 1 in ACT_HI_INCIDENT table.
Can you revalidate your scenario with refreshing table in DB?