I myself am having the same problem using Exterminate on two of my PC's, so you can rule out your PC's!
I have contacted the technical support team at PC Pitstop & I am sure this will rectified shortly
The following is a copy of my response:
Hello Tech Person,
I am sure you are aware of this situation, although it is quite
a recent development. When I try to run Exterminate it generates
an error once you choose "scan". It opens well but then crashes.
I am using Exterminate 126.96.36.199, Scan Engine Version 188.8.131.52 and
then here is the deal the Detection Signature Timestamp