Shadow too dark on one part of a Model

Development Rendering
1

I have a problem, the shadow in the lower part of this cup is defiantly too dark. Through, this model worked just fine, and didn’t had this problem before in a different scene (as far as I know, all settings for Lights and World settings are the same, yet it has the Problems only here - Both times I used Preview Build for Lights, also this is a moveable Object (also in both cases)).
Sadly I also haven’t found anything so far on the Internet that helped, but I am pretty sure I am just overseeing something major here -.- .

//edit: Found the cause: “Worldsettings → Envirenment Color” causes this, when its set to a darker color (default its black on new maps, so too dark)

http://nekros-blog.net/images/private/cup_bug.PNG

2

*Add a skylight (tweak your values till you find it appropriate) → in options untick lower hemisphere is black, build light and check if it worked!

Best Regards

3

Thanks for the suggestion, but all it did, was making all shadows lighter - the dark bottom is actually white itself (from the Texture), so the shadow color should be the same as the other inside shadows. (as they are in the other Project).

4

Weird behaviour.
Maybe normals of this part are inverted, double polys or something like this?

5

Not the Case, I already Tested the Model with new UVs and it dose the same also without Textures and as I said, its working fine in a different Project (both 4.7).

6

Found the cause: “Worldsettings → Envirenment Color” causes this, when its set to a darker color (default its black on new maps, so too dark)