there's dlc floating around that isn't decrypted,with nonpdrm SRW V is a good example, Gintama is another example, best to dump your own for that.(only way to be sure is your own private nonpdrm dump), even if you pull a license file from vita shell online database, it won't work at all!
PCSE############, game folder goes in ux0/app
game update goes in ux0/patch
DLC goes in ux0/addcont ...... (the license files for that goes into ux0/license/addcont
Add your own private nonpdrm dump, at least you know it works, "no pay station" may not work at all
get the DLC and add it to the right folder in your vita, then use "vita shell" and "refresh live area", if it does not add the DLC, try to refresh license database form vita shell and then "refresh live area" - you can add DLC or apply updates in any order