Blender 2.5 alpha

The new Blender doesn't work with Unity when I import a model from the new Blender. It says Blender couldn't import it to fbx??

Can somebody help me?

Blender 2.5 is alpha software and doesn't really work well with Unity at this point. Stick with Blender 2.49b until 2.5 is done.

Just use the FBX exporter and forget about using Blender files straight into the Assets folder. It's much cleaner and problem saving, believe me.