You probably have a linkage issue.
Open the top level VI on the machine that has the toolkit installed, and make sure that it opens without an error (the run arraow should be white). Press : ctrl + shift + run arrow. This forces a recompile of the code, and will update the internal links to all the sub-VIs. Then, save the top level VI, and close it. Open a new VI, so that there is only one VI in memeory, and it is a new (blank) VI, and try to build the applictaion again.
J