This error means that frame buffers were not created correctly. Check this link under "Framebuffer Completeness" section.

In some cases the application may apparently work as expected as certain OpenGL drivers try really hard to maintain functionality (typically Nvidia video cards), but it doesn't mean that everything is okay. Try running the same application on AMD and Intel video cards to see how it works.

If you could post the frame buffer's creation code, I'd take a look to see what's missing.