Upgrading to MonoGame 3.5.1 (from 3.5.0.1122) - Processor 'TextureProcessor' had an unexpected failure

Similar to MGCB: DXT compression sometimes throws NullPointer

@Zoltan_Ferenczfi @Peter_Kaegi
Can you reproduce the errors or it goes away when you rebuild the project?
I have seen the error from time to time, not always for the same texture.