rose lynx
With the Dev cycle of GTFO over, I decided it's for the best to gather up all the details on a long standing and highly problematic issue that I discovered during Alt rundown 2, and then put said details anywhere relevant so they can be found by anyone that has this issue in the future, so they can find some answers since I doubt the issue will be fixed.
I'm sorry to say you will likely not like these answers.
If you are using a FX 6300 series or a FX 8300 series CPU (other odd ball CPUs have been reported to have this issue), then you will not be able to join other players/have other players join you (unless in highly strict circumstances) in these levels: R2B4, R4A2, R4C3, R5D1 and R8E2. this is because of a error that happens when the level is generating.
GTFO generates it's levels when dropping down into them during cage drop. To put it in a extremely blunt and not entirely accurate way, it's like generating a Minecraft world with a set seed, that world should come out the same way every time (well in Minecraft there is still some variance I think). The error happens during this step, making it so the PC with the offending CPU generates a mismatching checksum (specifically LateGeomorphScan) then what is expected.
A checksum is how GTFO knows that the host and each client generated the same level. If a client's checksum does not match the host's checksum, that client is kicked from the game during cage drop. So in the case one player has a offending CPU, if they are a client, their checksum does not matches host so they are kicked. If the said player is the host, everyone else's checksum does not match the host's checksum, so all the clients would be kicked.