I see that on SSCUI 102364 there is a message existing in list ME n° 063 called Acct. assgt. category & not defined (please check your input)
When adding this new entry, a message error appears: ( any idea how to add the blocking message ? We want to make it mandatory to enter a value in acct assg cat and not let it in blank at the creation of the purchase order)
Select a key from the allowed namespace.
Message no. SV019
You tried to add a new entry, and when doing so, used a key value that lies outside of the namespace you manage.
This can cause problems in later upgrades because the entry could be overwritten by an import, or overwrite an existing entry.
Check your entry and try to enter a key value from your namespace.