Hello, there was a problem from the beginning in chapter4. You're not supposed to go down the crater with the rope until the end of chapter 4. First you have to find out what's in the coded blast door. Therefore, it is a mistake to be able to go down the crater and go to chapter 5 so soon. I have already corrected that. You can only go down the crater at the end of chapter 4.
You have to enter a code on the armored door. You have to add 264 + 264 because there are two signs with the same number and because Weena somewhere tells you that they are numbers that complement each other. So I thought that the one who put that armored door there (John Titor) put that key, the sum of the two signs, the only ones there are.
I'm going to fixing the other English spelling errors. Thanks!!