Texmaker and TeXstudio ⇒ Internal pdf viewer only works when embedded

[wvd]

Hi,

My documents compile perfectly fine when I use the external pdf viewer or the internal pdf viewer with the 'embed' option, but I would like to use the internal pdf viewer in a new window, and that does not work. I can see Texmaker opened a new window, (see attached image), but I can't open that window. The preview Windows shows when the mouse hovers over a window shows an empty desktop.
Does anyone know why this happens and how I can get it to work again?

Edit: I'm using TexMaker 5.0.2 and I've reinstalled the program, without any luck.