The file you posted seems to be corrupt or something.
Converting from a boolean to a string is actually very simple. Here is an example:
If you have basic LabVIEW questions like this in the future, I'd recommend that you take some time to search the NI Forums and possible Google. If you are still unable to find the answer you need, you should post in the official LabVIEW forums at http://forums.ni.com/t5/LabVIEW/bd-p/170