Hello,
In system user entity, I have created a custom field called "ClosedTime" (Text data type) and as "System Administrator" I am patching time value with following formula that throws an error:
"The requested operation is invalid, Server Response: Users failed:No modifications to the 'SYSTEM' or 'INTEGRATION' user are permitted."

The same formula was functional earlier, however today it's not working.
Any clue?
Thanks,