We can’t find a record-triggered flow named 'Update Cases When Contact Becomes Inactive'. Make sure you saved the flow with 'Update_Cases_When_Contact_Becomes_Inactive' as the API name.

Hey @Bhavana Dubey, main thing is as the error says make sure the flow has the correct label and api name as specified in the challenge and you are checking the challenge in the correct org 

Make sure there are no other flow versions apart from the one which you are testing for.

If you have created multiple versions of your flow, keep the latest one which you are trying to verify in the challenge and delete all the older versions.