So...this error occurs specifically when you do a getEntry call on a record that doesn't exist. The reason for it's non-existence is unknown at the moment. To fully understand the why, you would need to capture the API/SQL/Filter logs while the error occurs to figure out why a record that was being created ended up not being created.
do you get it while submitting service requests or service request definitions? Normally it happens when system tries to perform particular operation on record/s and it couldn't find that record/associated record anymore in the database and and hence system returns 302. most of times it also gets registered in the arerror.log file. You need to capture SQL/Workflow logs to find out the root cause.
you are just witnessing the defect mentioned in the below article :
While you're looking for solution, you can (manually, or via an escalation if you wish to avoid pile-ups) update erroneous records in CAI:Events form with Return Code = Error and Rtn Message Code = 302 by setting CAIAction to RETRY and Return Code to Start in order to retry creating such work orders.