I'm using Sierra also. Where did you download the program from? Was it the link on the IMSI website, from an e-mail or here in the patches & upgrades thread? My version is from the Patches & Upgrade forum link, so try downloading using that link and doing a clean install.
You are the first to report this problem, considering that you get the error before even trying to load a file, very strange. If that doesn't clear it up contact IMSI.