What are the minimal permissions required for the "Users and Privileges" tab in MySQL Workbench to function in MySQL 5.6
A partial answer: for just resetting Passwords, I was able to get it to function with CREATE USER, RELOAD, SELECT, and UPDATE.  For actually granting schema privileges to the user, it continues to give an error up to DBA.  For example, it successfully grants the privilege, but then throws the error about revoking (as mentioned above), then if you close the "Users and Privileges" window and reopen it, you can see the schema grant actually applied and saved, but you can't delete it (same revoke error and it doesn't stick like when adding).  I still don't understand what privilege is driving the error; much trial and error and process of elimination was done.