Multiplayer not working

[Ameba Da King]

Good evening,
I am trying to play with a friend of mine via ad hoc mode but it works ONLY with Metal Slug Anthology. I've tried all the servers on the list but it keeps giving me an error or simply disconnects right after connecting. We both have the latest version of PPSSPP but we run it in two different OS (Windows and Mac). Any suggestion on how to solve this problem?

[AdamN]

First of all, you need to mention what games are having problem, and also what kind of internet all the players involved are using (ie. are they behind NAT/shared internet connection? can they successfully opened the port?) if you're trying to play over the internet without VPN, also have you tried using VPN?

Are any of the players seeing a red/orange message on screen?

Most of the issue in adhoc multiplayer are related to firewall, restricted ports (< 1024), port forwarding, or very high latency (> 200 ms)

PS: AFAIK the only working public adhoc server are socom.cc and psp.gameplayer.club, but if you're playing on LAN you need to select the correct IP (don't use localhost)

[Ameba Da King]

The games are: Tekken Dark Rerruction, Asterix & Obelix XXL 2: Mission Wifix, Crash Tag Team Racing. We're both using Hamachi to connect to the server and disabled the firewall.
The connection problem isn't with the ISP but inside the games that say "connection to the other player lost" so we don't see any orange/red message

[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.