How to re-set a TER to Non Run
2 answers
If you refer to this diagram, you will see how Test Case Execution Records are related to Test Case Execution Results:
https://jazz.net/wiki/bin/view/Main/RqmApi#TestResRel
It is the Execution Result that has the status of Passed or Failed, not the TER. When you view a list of TERs, there is a "Last Result" column that shows you the status of the most recent Execution Result associated to that TER. You are right that you cannot change the status of an Execution Result to "Not Run", but you could delete an Execution Result that was created in error. This can be done from the Execution -> View Test Case Results list view by users with the Quality Management -> Save Execution Result -> Archive permission.
https://jazz.net/wiki/bin/view/Main/RqmApi#TestResRel
It is the Execution Result that has the status of Passed or Failed, not the TER. When you view a list of TERs, there is a "Last Result" column that shows you the status of the most recent Execution Result associated to that TER. You are right that you cannot change the status of an Execution Result to "Not Run", but you could delete an Execution Result that was created in error. This can be done from the Execution -> View Test Case Results list view by users with the Quality Management -> Save Execution Result -> Archive permission.