You don't provide a lot of details but my guess is that your old VIs are saved in an llb (bad idea) and that when you created the llb, you chose to include VIs from v.lib (even worse idea). Old LabVIEW functions in vi.lib get modified (bug fixes, enhancements, etc.) and that's usually not a problem unless you try to load the old functions with a new release. If you do have an llb with vi.lib functions, make a copy of the llb and then delete everything except the VIs that you wrote from it. Then when you load your application, it will use the NI functions in the new release. You can also open the old top level VI and look at the hierarchy. If you see any VIs that point to an llb or the vi.lib folder in your old version of LabVIEW, go into the VI that calls these, right click on them and do a replace.