Installer maker window keeps blank on OS X

[Tiemo Hollmann TB]

Hello,

 

I am packaging my OS X program with installer maker and codesign it. It
works fine at all customers beside of one.

Now a customer with OS X 10.9.5 tells me that she opens my installer and he
gets only a blank white window. The window has my text in the title bar, but
not text or any buttons like cancel or next in the window, so she can't go
on to install my program, only close it by the red cross.

 

I have checked, if it has anything to do with the security settings (install
apps only from.), but nothing changes in the weird behavior of the
installer, changing the security setting. The user has admin rights.

 

Has anybody ever seen such a behavior, perhaps with any other program or any
idea, what to check for on this machine? What could go wrong here?

 

Thanks for any ideas

Tiemo