Just to confirm: You had evaluation v12.2 working fine (and now expired) and recently installed evaluation v13.0 in which you got this error message?
Did you already try uninstalling all instances of OptiSystem (as there may be a licensing conflict between the two evaluation versions)? Also, installing on a new computer should definitely work.
While you try that, I will ask our Office Administrator to arrange for a 15-day extension of your v13 evaluation.
Cheers,
Bryan