Symptoms

Issue
The client was unable to open k2 designer as the query to SQL would time out and then raise an error of root element is missing
 

Diagnoses

Diagnosis:
We found that there were some +- 125 process instances linked to +- 7000 events that was completed but never archived or stopped.
 

Resolution

Resolution:
We completed the process instances that we found by updating the status to Status + 100 to allow us to identify the processes later if needed and to ensure that k2 does not try to action these processes.

After this was done we restarted the k2 hostserver and the performance was back to normal and the client was able to open designer.