It sounds like something has changed on your computer, if you were able to calculate files with the same version previously and now you can't.
Some things that could trigger this problem might be an update to your operating system, an update to your antivirus software, the installation of a new program that for some reason interferes with THERM.
A few things to try, although I suspect they might not help.
Run THERM as an Administrator
Try running one of the sample files that is in the default THERM working directory, and see if you have the same problem.
Robin