I couldn't find this issue on the Internet which means that you're probably doing something wrong or the Vtope application was corrupted. Try installing it again and check its requirements. If it still doesn't work after this procedure, use the email in this answer to send an inquiry to the developers explaining the problem.
Sometimes when you upgrade an application it breaks compatibility with the operating system. It's possible that it happened as well here.
- Support email: firstname.lastname@example.org