Recently one of our users got the below error
The error message is bit incorrect here. The error was because the user had User Level Read Access to the record or (Entity to be specific) and on saving the record, we had one of our real-time workflow being triggered which was assigning this record to another user. And on assignment, the record being getting assigned to another user, the user who had created\saved the record was losing the access to it.
Hope it helps..