PluralEyes 4 uses HTML5 technology. Software that monitors or filters network connections can interfere with this application launching.
1) Check to make sure PluralEyes 4 is an "approved" application in your network security settings.
2) Turn off any internet filters you may have on. Some filters may prevent PluralEyes 4 from launching.
3) If you are still having problems, contact Red Giant Support and provide the following information: