The proper way to do force host involves more that just writing to 1 address. This is because it can change from computer to computer, even if it seems to be at the same address for one person.
This is the REAL way to do force host for those wondering. We will be using the party_minplayers dvar. The location of the dvar can be found using the dvar pointer at 0x01409014. So, first we read the integer (which contains the address to the dvar struct) at 0x1409014. Once we have that value, add 0xC to it. Now, write 1 (to set the minimum players required to 1) as an integer to that added result.
Example:
The value in 0x1409014 is read and we get the value 0x500000 (this is not real, I made it up). We add 0xC to that value so it becomes 0x50000C. Now, write 1 as an integer to 0x50000C and you've successfully forced host. This will work on every computer and there is no more problems about force host not working.