This appears to be a coding error that is directly related to the way the software was coded. You can't much about it because you would have to be the developer to look into the message and the way the software works. Unfortunately, there is no information or any contact details about the developer of TM ECGVue. If you still have it installed, go to the installation directory and look for README files or any help files. Search for contact options and contact the developer while attaching the error above.