Well, here we go again...
I have seen this error way too many times in my day.
The problem is you have a bad linkage, or unsaved or compiled VI in your hierarchy when you built the application.
Open your main, or otherwise open (into memory) ALL VIs in your hierarchy. Then, do a save all from the file menu. This should solve the issue.
The other reason I have seen this is if you have bad linkage. As there is no real way to tell what your linkage is, you need to go into the hierarchy, select View Full Path in Title and make sure everything is where you think it is. I have often seen this occur even when the application I was building from was in perfect condition. Often times, when the app builder is used, VIs will be called from locations you
don't expect.
You have to be VERY careful about developing in a hierarchy. I actually got to a point where I had to even place all the NI VIs into my directory structure.
Take a careful look at the hierarchy. Chances are the executable is calling the wrong code, or is compiling with the wrong version.
If in doubt, go to a fresh machine, and move all of your VIs (individually if you have to, or as a .llb preferably) to the new machine and build it from there. Alternatively, you can try doing a save as from your main and select "application distribution" this will resolve any issue with VI locations, except where Dynamic VIs are being used.
Good luck, 'cause you are going to need it.
