My character Azgug on Thornblade is unable to make the Potion of Accuracy TLP edition, I get the "You cannot make this combine because you fail to meet the requirements." Each time I zone I get a Mercenary Message as well. This isn't my only character that gets it seems a few that I have created in the last month or so have that, or name changed recently.
What components are you combining? TLP recipes also are only available until a certain expansion unlocks (I think when it hits the TS revamp, even though its "still a TLP"). Don't put 2 different issues in one bug report.
Soulbanshee is correct, TLP alchemy gets a revamp in PoR which Thornblade is now past so they are on "normal" alchemy now.