here with a completely new shader... the problem persists

oh, comnpletely empty, tried it with just a single diffuse texture... but i migrated the shader from an old version and therefor ther are still nodes in the graph... but unconnected for finding the issue. As the shader is quite complex i dont want to redo it from scratch. Any ideas what to do?

I ll try to test it with a new shader and report back in a minute...