What you're going to need to do is put your device into Pwned DFU, and see if that works. To do so, download
You must login or register to view this content.. Then:
1. Open in administrator mode, and click on Extras > Pwned DFU and follow the steps given.
2. Once done, close out of redsn0w and open greenpois0n.
Tell me if that works.