I have tested and gotten the same results to happen enough times that I have found some absolute, definite causes for the ???? error and they're not all the same.
1. The BS reason they give for every case is that your graphics card isn't up to date. That's probably responsible for a whopping 1% of the ?????? errors though. The game uses directx 9.0c so that is absolutely true. If the game runs a graphics process that's in 9.0c that's wasn't in the 9.0 original that most cards were built for, it can go BOOM ??????
Go to your manufacturer's website and find the latest driver for your specific card and install it.
2. gameguard detects certain outside programs doing things. There's something I can do in another program unrelated to SRO that crashes the game with the ????? error about 75% of the time. It's possible this is related to a graphics conflict but it's more likely it's gameguard.
3. if you're hunting near a person with a laggy connection, usually because they're playing in another country or running a p2p program, that will repeatedly crash the game. I tested that almost a dozen times with different people and if you stay within selection range of them for long enough, it crash for both of you over and over until you get further apart. Sometimes your character even seems to teleport quite far every 2 seconds in one direction. I could only get it to skip me across the map like that 4 times and it crashed when I hit into a large hill at the edge of the map most of the time
I'll try and screen record it next time cuz it's actually really funny.
Here's basically how it goes. If you both try to attack a monster at the exact same time and one person lags so much that they don't receive the data that the monster was already killed by the faster person OR the slow person's killed the monster in their client but lagged so much that it didn't upload the fact that the monster is dead to the server until the other person was already attacking it. Then when two people's clients ask for full exp from the same monster...well boom ?????
Sometimes the non-lagging person keeps running the direction the monster was in if the timing is perfect but it doesn't run the running animation because it can't find the monster and you get the weird teleport effect. Could be caused by something else but anyway, don't hunt near people that are really laggy and skipping all over the place! And if U see me being teleported by an invisible force across a field, say cheese cuz I'll be recording it
4. In town hundreds of people crash with the ?????? error in one area all at once. Usually in Donwhang. I think we've all seen this. I've never seen it happen without it also happening to me, mostly because my computer is the type that causes it. I'm not sure if there are other causes but I accidentally found a way to do it on purpose and got it to work twice in a row. And it really makes sense why the cause causes that effect too. Before you even flood my inbox,
NO I WILL NOT TELL YOU HOW because I'm sure some dumbasses would do it all day and the towns would be pretty empty. I suspect a similar lag problem as I mentioned above may be to blame the rest of the time. Either way it has to do with a difference between the timing of data that one player receives and the data that another receives and then them both acting on it in conflicting ways. It disconnects everyone in like a 150 foot equivalent area as a protection method otherwise everything would pretty much go crazy. Joymax either doesn't know the exact cause or they like getting rid of stalls when it's crowded to let more ppl on. The only reason this happens when the servers are crowded though is because it's more likely that someone will do what causes it on accident and the server is more laggy for everyone in general, it's not a complete conspiracy and they didn't code it to do that on purpose. Okay on second thought, I'll tell you how it happens so you can STOP DOING IT. DO NOT close your stall while there's people in it or else BOOM ?????. Stall owner or buyer is lagging a lot, buyer buys something,
one more essential thing happens that I will leave out so you immature noobs can't do it on purpose, and the server gets the message that someone bought an item from a stall that doesn't exist and ignores it and disconnects everyone in the area in case it was someone trying to do a duplicate item glitch/hack or it was a glitch that would destabalize the whole game (like duplicating items in an infinite loop, lol) So again
DO NOT close your stall while there's people shopping at it because if they buy something at just the wrong time when you're closing it, there goes everyone. There's other ways it happens in town that I know about too that hopefully Joymax will stop ignoring my bug reports about
But simply,
STOP LAGGING, EVERYONE and it will be less of a problem.
5. this one I haven't completely proven but it's awfully suspicious. They have lots of protections in place as just in case types of setups so that people can't use hacks and glitches to do cheating stuff like duplicate items, attack 10x in a second, get exp from the same monster multple times, run faster than the max, etc. If you're lagging and you double click one monster then another near it and kill both but lag for the couple seconds it takes to swing your weapon twice (assuming you can 1 hit kill them) it will upload/download the result of the kill function and decide you killed two at the same time and BOOM. It could be a coincidence and they protect it with timestamps but like I said, it's awfully suspicious that I got it to work a couple times while I lagged it on purpose with bittorrent
So again, STOP LAGGING and you won't have a problem.
6. yeah it's another lag one so I'll be quick
your computer is out of resources and it's lagging because of that because it can't accept any more instructions to the processor for a little while. The server runs some lines of code that say a monster just spawned next to you and attacked you but your computer is still stuck processing your "move to where I clicked" instructions and when it finally runs through those, the monster attacks you from further away than it could have run in that time and BOOM ??????? Stop lagging dammit
kinda the same thing, they lag and all of a sudden it's like OMG I'm being healed, but I clicked to walk out before it started? BOOM! ?????????