"Blue"-Parts of Car textures are completly black?? also with a skylight etc

Hello UE Community… i have several problems / bugs with the unreal engine and i dont know why !
My Police car has 1 texture which contains blue parts and yellow party, but only the blue parts are completly black?
Few weeks ago this works fine and all parts of the car were fine … i dont changed anything on the engine settings or on the car

Iam using a Skybox, a Directional Light and a skylight - has anyone a fix for this … ?

In my BP Editor:

metallic materials need reflection captures to work