To me that looks like the DAZ installer hasn't initialised properly, maybe try redownloading your V4 files and try it again.

I actually use Poser 7 even though I have 8, but my V4 is installed in Poser 6 where all my stuff goes. Poser 6 is my install programme, I use 7 but render inside Vue 8.5.

Now here's the thing, when I got this PC, V4 was already installed on my old machine in the P6 runtime. I re-installed all my poser apps and then copied the saved runtimes into those installs, so technically V4 has never been installed on this machine I suppose...
I have no issues though, try a redownload, it could be corrupted..

Injustice will be avenged.
Cofiwch Dryweryn.