My condor won’t cock

I bought a condor frame from AOA it’s the old style I think has the red cap safety, which I took out. I bought this to put one of the air archer kits I picked up from another member, got it all put together and it won’t cock not sure what the problem is, the spring is very strong with a brass hammer when you try to cock it, it just won’t catch I’ve even tried with the hammer that came with it an have the same result, can anyone give me a different idea to look at. Thanks Terry 🙁