Details shared internally!!! 

1. Execute the test in attached project. 

2. The step 'Click SaveButton' in the popup closes the popup so it has the property 'ClosesBrowser' enabled. 

Expected: to execute all steps successfully

Actual: the last 'Close Popup' step fails 

The workaround is to insert an execution delay between the  'Click SaveButton' and 'Close Popup' to ensure the actions will be synced.