Try
/define/boundary-conditions/set/wall/ce2 () /uds/no/500
I've added a / at the start & a space after / Otherwise run through the command piece by piece to see what's going on. Ie
/define/boundary-conditions
/set
/wall
ce2
()
/uds
etc
You're looking to see what's complaining. I assume you've already assigned UDS in the User Defined panel?
You are navigating away from the AIS Discovery experience