Hi,
The parameter DY_SELMO is protected so difficult to change. It should be set to '0' automatically. Any other value is probably from a lower release and is considered a inconsistency. To check the current value:
Run IH01, Selecte menu option 'Goto - Variants - Display'.
Select the relevant variant. Check the value of DY_SELMO.
If there is a value X then delete the variant (via SE38) and re-create new version of this variant. Checking the value again should show value '0'.
-Paul