Error when trying to update existing validation rule - "Validation rule with the same expression already exists"

Version 1

    Details

    Customer The customer wanted to update the message for this existing Rule as its incorrect
    and is getting an error when trying to change the validation rule.
    He also.tried deleting the validation rule and it says it doesn't exist


    Error:



    There is no duplicate rule.

    I have even attempted to delete the rule to recreate it but I get a conflicting error:


    Resolution

    With the changes that have been made with Rule Formatting in the last few versions - sometimes you get these errors when using the old format/logic

    .By pressing the 'Simplify Expression' link at the upper right, the expression changes (but will still work) and it will then allow a Save.
    These older expressions will still work, but in most cases you can no longer modify them and keep the old expression.