Hello, I just bought a used 3Gs. Found iOS 4.0.1, restore and update my phone to that. Went onto jailbreakme.com and now im getting "oops file received was invalid". How can I fix this?
try restoring with a 4.0.1 firmware file by doing the shift (windows) or option (mac) and selecting the file you downloaded from wherever [just google it]
make sure you don't just hit restore, or else it will download the one from apple (4.0.2) and you won't be able to jailbreak
unplug it, and your golden.
hope that helps. if not. good luck!