TextMesh somehow fails to render correctly

Hey everyone,

The TextMesh in my Scene doesnt render correctly and I dont know why.
I created a completely new project, added a directional light and a cube and scaled it 5-5-1.
Then I added a TextMesh to the cube, set the text to "Test", the anchor to middle-center and the font to the default arial font from Untiy. Everything else is left default.
So now it looks like this:

But as soon as i hit start, it changes to this:...

TextMesh somehow fails to render correctly