Hi!
I'm sorry you've run into issues. Have you seen our documentation?
http://www.infopathdev.com/files/folders/qrules/entry59157.aspx
http://www.infopathdev.com/files/folders/qrules/entry61475.aspx
If so, please let us know when that error is happening, and we'll take a look at the document to find the possible causes.
Thank you.