TTF Fonts in Unity's 5.1 Are Not Showing Up

I’m using Unity 64 bits in Windows 10

It doesn’t matter if I’m using the native UI System or a 3D Text Mesh, the ttf fonts I chose are being displayed as Arial.

I’ve installed Unity 32 bits and the same issue occurs.

Is this some incompatibility with Windows 10? Am I the only one having this issue?

Thanks

-----------EDIT-------------
OTF Fonts are working just fine. This is very strange

I have problems with some true type fonts too, where they simply render as Arial.

I filed a bug-report in Mai 2015 (Case 697294) about this issue. Here is Unitys reply: