Maybe when the 32-bit version was installed, you didn't install the add-on or driver or whatever is missing? There is an astonishing "lack of detail" in your question -- the only solid point is that you have both 32-bit and 64-bit LabVIEW (presumably, not not explicitly stated, the same Version, e.g. both "LabVIEW 20xx SP1").
An "experiment" to do would be to take a fresh PC (or a new VM) without LabVIEW and install only the 32-bit Version. Can you get it to work? If so, can you "add" 64-bit LabVIEW "on top of it"?