These last few days all four Ys Steam titles have been updated frequently, seems the Ys1+/Ys2+ trainers were just updated to be compatible so the two remaining ones (Origins and Oath.) will probably be updated shortly as well should it be required. (Though I haven't tried the new Ys1/Ys2 trainers yet so I don't know if it's compatible with today's update of the game.)
(No idea what they are updating the games so often for, in the launcher there's a setting for joining Ys1 with Ys2 but I don't know how it works and there's no info yet on what the specific changes are other than that.)
Strange how the Ys games haven't had any activity in a long time then these last couple of days they have all been updated around six times or so by now, heh.