Cubase 8 Pop-up window malfunction

In Cubase Pro 8 (using Mac/Yosemite) I can only open the window to import audio once - then this window doesn’t appear when pressing “import audio”. The same goes for importing a library in Kontakt - works only once, then you have to restart cubase for it to work again. I just tried to go back to Cubase 7.5 - and it works perfectly there, so it has to be some sort of bug in Cubase 8 doing this.
It’s EXTREMELY annoying, What can I do to fix this??? Please advice.

Everything, cubase, iLok etc etc is up to date.

Hi,

What are next steps, please? Is it the same, if you select any File and import it, and same if you click Cancel?

Is it the same, if you use OK button and if you press Enter?

How do you call the import window (menu entry, Key Command, HW controller…)?

Thanks for details.