Image Effects on the GearVR?

Hi, I am trying to use image effects in my GearVR project but it is simply not working.

While I am inside the Editor everything works well but as soon as I test it on the Gear the image turns grey. If I only apply the effect to one eye, the one eye will be grey.

The Effect used for these tests is Blur.

Any Ideas?

Do I have to change something in the OVRManagerScript?