1. Install Fiddler and open the program while your project is running (You can download it from http://www.telerik.com/download/fiddler).
2. Open Fiddler and then, click the Win8 Config (or WinConfig) option located in the toolbar.
3. The AppContainer Loopback Exemption utility window is opened. Search and
select Bizagi in the list displayed.
4. Save Changes.
you have performed the procedure above, this issue be resolved.