In the past I was able to easily edit already existing activity records but today the system started to display an error message stating that "The action that you are intended to perform is not possible" when I edit some of the existing records. I find the modifications to have been applied when I check the records by pressing the "Go Back" button on the error message. I'm not aware if this happens on all of them or on only a subset of them. Could you please take a look at this issue.