Unfortunately I'm getting this error as well. I ignore it and sometimes it repeats within seconds, sometimes it lets me play for a few minutes. After a few times of pressing ignore the process just terminates!
I see that the couched lance can only stay down for 5 seconds. I would prefer no time limit at all. Have no problems pressing X to activate.
Otherwise I'm very happy with this patch. The layout and artwork are great. Also as a multi-screen user I'm very pleased that the HUD and menu is no longer stretched across 3 screens but is now nicely centred on the centre monitor Thanks very much devs - it seems you guys have us multi-screen guys in mind as it says "multi-monitor mode enabled" when I start the game up.
EDIT: I'll try the edit mode suggestion - yep seems to solve the error coming up.