Runtime error for QT application?

The error was

Fixed the problem:

The fix is add a folder platform into the location of your application executable and into that copy qwindows.dll from the loaction 5.1.0-rc2\mingw48_32\plugins\platforms of your QT installation.

Also all the dlls need to be copied!

It seems like you have missed some DLLs. Try again with dependency walker, I have faced the same issue once. The dependency walker did not show missing DLLs but some were missing. Try to search in SO, there are similar questions.

Do I have to include all these Qt dlls with my application?

How to run Qt 5 applications on other computers (Windows 7)