iOS Build - Unable to validate signature

Hey there,

So, I started working on an iOS Build of our main project line. I get through building, but run into an error when using iPhonePackager.exe

I tried the same certificates, mobile-provision etc. on a new, empty project and it works there.
So the question is, how do I find the exact source of the problem? Have you had the same issue before? What further steps would you recommend?

Any bit of info is much appreciated, thanks ahead!

Sidenotes:

  1. I am on Windows, but I use a Mac on the network for remote compilation
  2. I did try to install the application via iTunes and the icon remains greyed out after installation.

EDIT:

Launching the application with the default iOS Settings produces an ipa that does not lead to these results. It can actually be loaded onto the device. However, this version is stuck on the splash screen if started