I installed Mantis with the help of XAMPP.
Using this video present in youtube i did the installation:
But in this video they showed the installation of older version of Mantis, which I did using the latest version(Mantis 1.2.19).
I used the following version of XAMPP (xampp-win32-5.6.14-0-VC11-installer).
I have created Administrator, reporter and Developer accounts. And this issue occurred in one of the Reporters PC. He used Chrome browser to login into Mantis.
The Administrator has created a New Project and the reporter tried to report an issue in that project. After selecting the "Submit Report" button, it was taking long time to load "Operation Successful" page. Instead of that a blank page was displayed.
When we tried to refresh the same page, "Operation Successful" page was displayed but the same report is generated with two different ID's.