I have been waiting to play swc for over 3 weeks now and i keep getting this same message
"Your handle does not match out current rules requirements. It was turned down
because of the presence of a restricted name or adjective, such as ?Lord?,
?Count? or ?Darth?, or an existing Star Wars character name was chosen such as
?Luke Skywalker? or ?Han Solo?. Please refer to the Character Creation rules
page located at http://rules.swcombine.com/character/charactercreation/ for more
even though i use the random name genereator and names irrelevant to star wars, i cannot use any name
The handle you posted was probably rejected because Mission is an actual word. It shouldn't have been, given that Mission is also the name of an actual character, but the person who rejected it may not have known that.
Without knowing what other handles you tried I can't speculate on why they would have been rejected. If you really want to use the name Mission you can just try again and hope someone else sees the handle request who recognizes it as a name. Otherwise, just try a handle that isn't an existing word and that should work as well.