@andreyc yes, it creates calendar event and sync with google calendar but i cannot display my event title in calendar date itself.

Thanks a lot! I put it in AppWindow object and it works.

Thank you everyone :)

I followed simow and SysTech's suggestions and used QDebug to find the problem. I found my program crashed when entering a certain set of libraries so I ran the release executable through the debugger. The stack trace of the assembly revealed that my code was using the debug versions of my third party dlls even though I thought I specified my project to not use them in the release version. I modified the .pro file in qtcreator and now everything works properly. Thanks!!!