ZV Parent Master 1.3.3 for Maya (maya script)

I atached my one of my ik hand to a referenced file, then detached it, and then i decided not to use this referenced file, so i uncheck it in the reference list. After that, i made changes on the original reference file, and go back to my scene, referenced the reference file again, and imported it, the old one was still in my reference list with unchecked. And then I found that i cannot atach the ik control to the newly referenced obj, and i figured out why, so i check on the old reference file in the reference editor and imported it also, and atached my control to the new obj, it worked again, everything works fine. And after a while, i decided to delete some obj which is unusing in my scene, including the old referenced obj, and i deleted them. After i doing that, i found my ik hand is atached to the new obj forever, i could not atach it or detach it, even i could not destroy the control. And i get this error:
# Error: ValueError: file C:/Users/qinqing wang/Documents/maya/2016/scripts\ZvParentMaster.py line 140: No object matches name: GeorgeStevens_mod:hero_ac_lf_handIK_PH_PC.w0 # And even if i use unparent, it then could not atach to anything, and i also get the same error.