pop up a box "fatal error" ??

Hi,

who can focus on my ques.?

when I have editted the path on RS,I try “move on path” instruction,it can works, but when finish running,it always pop up a " fatal error" box saying " An unhandle exception,". but,it doesn’t affect my programme when I put it in RSonline.Maybe it does exist some problems in it, but I don’t know ,who can be favour to give me sugg.

thanks a millions