I've been hearing that people have been having trouble with MogStation for the past few months because SE changed payment providers, but I didn't experience any problems until today when I tried to top-up my Crysta so I can resub. Got a bunch of unhelpful error messages and codes, and SE's support site looks like it was made in 1999 so writing up a support ticket was significantly more complex than it should have been.
Eventually my payment went through (presumably due to one of the dozen things I tried) but what a pain in the ass...
Anyway, time to work on my Viper glam.
Edit: Seems to be a common issue right now.
If you haven't resubbed or added Crysta recently, you might want to double check if it works before you're locked out of Dawntrail early access because of this bs