I had this problem some time ago with ASCOM, from memory it was one of ASCOM's ini files got corrupted. Can't remember what steps I took to remedy the problem but I did get it fixed.
I think MAYBE I deleted the eqascom.ini file and started ascom again and all was fine.
Again, was long ago, so don't take as gospel.
Edit:
Found these:
http://stargazerslounge.com/topic/12...runtime-error/
http://stargazerslounge.com/topic/10...time-55-error/
http://stargazerslounge.com/topic/12...g-no-idea-why/
I realise it's a different mount, but could still be similar fix with the AP ascom ini file.