If issues persist
On the PC, Street Fighter X Tekken had a controversial release where 12 characters (known as the "DLC 12") were shipped on the disc but locked behind a paywall. When the PC version received Patch 1.08 (which added the 2013 balance update), the community discovered that the data for these characters was fully accessible. street fighter x tekken pc patch 1.08 character unlock
“You can unlock titles that can be used to customise your battle profile by clearing Arcade Mode and by clearing each character's specific trials.” GameFAQs If issues persist On the PC, Street Fighter