ERROR: FrameBuffer: -1 has caused a GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT_EXT exc

[EgonOlsen]

Ok, here you go: http://jpct.de/download/beta/jpct.jar

This version will print out all texture names (base, normal and bump). It doesn't distinguish, which one of those is missing. But apart from the software renderer, there should be only one texture name anyway and the rest will be null, so it should be easy to track it down.

[AGP]

Thanks very much. That solved two thirds of my problem. But I still got one "ERROR: Tried to set an undefined texture!" with no texture name. The message must be printed in more than one place!

[EgonOlsen]

Yes, but those other methods are actually for the software renderer only...i somehow doubt that you are using them. Another place is when you are adding a TextureInfo with a faulty id in it. At that stage, i don't know any texture names. You have to check the getTextureId() for it's return value in that case (assuming that you are using this to create the TextureInfo).
I've updated the jar with a version that adds the name to the mentioned methods, but as said, i doubt that this causes your problem.

[AGP]

It was the TextureInfo one, thank you. All solved (still wish I there was a safe and clean way to test for the shadow map's supported size, though).

[EgonOlsen]

Yes, but there is none, i'm afraid. The size actually is supported, it just doesn't fit into memory. The only way to detect this is to try it.