Exported ttf file font shows questionmarks

1

Hello, I am trying to export my font as a ttf file. But when I do so and I open it with FontBook, it shows almost all letters as questionmarks, execpt a few fx. L. I dont understand whats going on.
Any suggestions?

56
561938×532 29.7 KB
42
422860×1224 205 KB
30
301774×930 102 KB

2

I think I figured it out
Thanks

3

This is probably a font cache problem. Read this please:
http://www.glyphsapp.com/tutorials/eliminating-font-cache-problems