Multiplayer not working

[AdamN]

If you are using VPN such as hamachi, you shouldn't use public adhoc server like socom.cc etc. you should use built-in adhoc server with the VPN IP, if you use public adhoc server the connection won't go through the VPN since most free VPN doesn't have internet gateway, or through the VPN (if it have an internet gateway) but ports usually blocked unless your VPN have a settings to allow port forwarding (usually paid service)

"connection to the other player lost" are just in-game message, while the actual issue can be blocked port (ie. port forwarding issue) on one of the player or a very high latency, there is also a possible issue due to high rate of lost packets.

You should follow this guide to test if any of the player have blocked port or not https://github.com/hrydgard/ppsspp/wiki/...rts-or-not
All players need to be tested, since most adhoc games are p2p, thus all players must not have blocked ports.