Anno 117 Multiplayer Not Working? ROMUS-58080-0D Error

So you and your friend finally sit down to play Anno 117: Pax Romana, hit Multiplayer… and boom — ROMUS-58080-0D, infinite loading, or the dreaded greyed-out Load Game button. You stare at the screen wondering if your internet just died, if Ubisoft Connect is acting up again, or if you somehow broke something without touching a single setting.

Here’s the good news: it’s probably not you. And it’s not your PC, your connection, or your save file either. The bad news? Multiplayer in Anno 117 is currently a bit fragile under the hood.

Right now, co-op can work — but it’s extremely picky about how you start a session, who joins first, and when the game loads. One wrong step and you’re stuck in an endless loading screen or staring at a greyed-out button wondering why this feels harder than building a Roman empire.

Let’s break down what’s actually going on and, more importantly, how to avoid wasting another hour just trying to play together.

The Short Version (Do This First)

Before you go digging through settings or blaming your internet, try this exact setup — it genuinely fixes most ROMUS and loading issues people run into.

Both players fully restart the game
Not just to the menu — completely close and relaunch it.
Host creates a multiplayer lobby
Don’t load a save yet. Just get the lobby up.
Friend joins the lobby first
Make sure everyone is fully connected and visible in the lobby.
Only then does the host load the save
This part matters more than it should — loading too early breaks things.
If a desync happens, load an older autosave
Avoid the most recent save; it’s often already corrupted by the desync.

It sounds simple, almost too simple — but this flow fixes a huge chunk of ROMUS errors, greyed-out load buttons, and infinite loading screens. A lot of multiplayer pain in Anno 117 comes from the game being extremely picky about timing and session order, not from anything you’re doing wrong.

What Is ROMUS-58080-0D?

ROMUS-58080-0D (sometimes shown as ROMUS-508080-0D) is basically Anno 117’s way of saying:

“Something went wrong syncing everyone into the same multiplayer session.”

The good news?
It’s not your PC, not your internet, and not a corrupted save.

This error usually pops up when the game gets confused about who’s in the session and what state the game is supposed to be in.

It most commonly happens when:

Someone joins after the game has already started
The lobby state and the active game state don’t match
Crossplay has a small sync hiccup
A previous multiplayer session didn’t fully close before starting a new one

In short, it’s not a performance issue — it’s the game’s multiplayer session logic tripping over itself.

Once that happens, the game struggles to resync players properly, which leads to infinite loading screens, greyed-out buttons, or the ROMUS error popping up again and again.

Why Multiplayer Feels So Unstable Right Now

1️⃣ Joining a Game That’s Already Loaded

This is by far the biggest culprit behind most multiplayer headaches.

If the host loads the save before everyone is fully in the lobby, Anno 117 tends to completely lose track of who’s supposed to be in the session. When that happens, you’ll usually see one of these:

The “Load Game” button is greyed out
A ROMUS error pops up out of nowhere
The joining player gets stuck loading forever
Or the game just soft-locks and refuses to cooperate

What’s happening under the hood is that the game locks in the session state too early. When someone tries to join afterward, the game can’t properly sync them, and everything starts to fall apart.

👉 The fix is simple but crucial:
Always make sure everyone joins the lobby first — then the host loads the save. Never the other way around.

It sounds minor, but this one step alone prevents a huge number of multiplayer issues and saves a lot of frustration.

2️⃣ Desyncs After 30–90 Minutes

Even if you manage to get into a game without issues, things can start to fall apart after playing for a while. A lot of players report that sessions become unstable somewhere between 30 minutes to an hour and a half in.

Common signs include:

One player suddenly freezing while the other keeps playing
A desync error popping up out of nowhere
Getting kicked out and being unable to rejoin at all

What’s likely happening here is simulation drift. As the game world grows — more cities, more production chains, more AI calculations — the game struggles to keep both players perfectly in sync. Eventually, one tiny mismatch snowballs into a full desync.

Once that happens, the session is usually done for. Even if you try to reconnect, the game often can’t reconcile the different states anymore.

That’s why longer co-op sessions feel riskier right now — the more complex your empire gets, the higher the chance the game just… loses the plot.

3️⃣ Crossplay Is Touchy

Crossplay technically works again, but it’s still pretty unstable and can behave differently from session to session.

If both players are on PC, it’s often worth trying this first:

Turn crossplay OFF
Restart the game
Try connecting again

For some setups, this immediately clears connection issues or ROMUS errors.
That said, weirdly enough, some players report the opposite — turning crossplay on fixes their session instead.

So if one setting doesn’t work, flip it and try again. It’s not elegant, but right now crossplay can be unpredictable depending on platform mix, session history, and matchmaking state.

Until things get fully stabilized, crossplay is very much a “try both and see what sticks” situation.

4️⃣ Starting Too Many Sessions Without Restarting

This one’s easy to overlook, but it trips up a lot of people.

If you:

Start a multiplayer game
Leave it
Start another one
Repeat that a few times in a row

…the game can quietly bug out in the background. At that point, you’ll start seeing failed connections, infinite loading screens, or ROMUS errors even when everything else looks fine.

Anno 117 doesn’t always clean up multiplayer session data properly when you bounce between games, so things slowly get more unstable the longer you keep going without a reset.

👉 The fix:
Do a full restart of the game before starting a new multiplayer session. It clears out the leftover session data and gives you a clean slate — often enough to make everything work again.

✅ Best Fixes for ROMUS-58080-0D Error

Here’s what actually works — ranked from most reliable to situational but helpful.

✅ 1. Restart Both Games

Simple, boring, but shockingly effective.

Fully close Anno 117 on both PCs and relaunch it. This clears out broken session data that the game doesn’t always clean up on its own.

✅ 2. Always Join the Lobby First

Never invite someone into an already-running save.

The correct flow is:

Host creates the lobby
Friend joins the lobby
Then the host loads the save

Skipping this step is one of the fastest ways to trigger ROMUS errors.

✅ 3. Load an Older Save After a Desync

If a desync hits, don’t reload the most recent autosave — it’s often already corrupted by the desync.

Instead, scroll back and load an older autosave or manual save from before things broke.

✅ 4. Toggle Crossplay (Off → On or Vice Versa)

This one feels random, but it genuinely helps some setups.

If crossplay is on and things won’t connect, turn it off and restart.
If it’s off and things aren’t working, try turning it on.

It’s clunky, but effective more often than you’d expect.

✅ 5. Keep Sessions Short

Long sessions increase the chance of desyncs.

If you want smoother co-op:

Save regularly
Exit the game every hour or two
Restart before continuing

It’s not ideal, but it dramatically improves stability for now.

Is This a Server Problem or My PC?

Short answer: it’s not your PC.

If all of the following are true:

Single-player runs perfectly fine
Your internet connection is stable
Other online games work without issues

…then this almost certainly isn’t a hardware or connection problem on your end.

What’s actually happening is that Anno 117’s multiplayer backend is struggling to keep sessions in sync, especially during joins, reloads, or longer play sessions. When things fall out of sync, the game doesn’t always recover cleanly — which is why you see ROMUS errors, infinite loading, or broken lobbies even though everything should be working.

In other words:
Your PC isn’t failing.
Your internet isn’t failing.
The multiplayer session logic is.

This also explains why restarting the game or changing the order you join can magically fix things — you’re basically resetting the session state so the backend can line everything up again.

So if you’re pulling your hair out thinking something’s wrong with your setup, you can relax a bit. This one’s on the game, not you.

Is Ubisoft Fixing This?

Short answer: yes — but slowly.

Ubisoft has been working on multiplayer stability behind the scenes. Recent patches have:

Fixed several known causes of desyncs
Improved how multiplayer sessions sync between players
Re-enabled crossplay after stability improvements

That said, multiplayer still isn’t fully rock-solid — especially for longer co-op sessions where the game has more systems running and more chances for things to drift out of sync.

So while things are definitely better than at launch, they’re not perfect yet. Expect gradual improvements rather than a single patch that magically fixes everything. For now, using the workarounds above is still the best way to keep co-op sessions playable without constant frustration.

The Honest Verdict

✔ Multiplayer can work
❌ It’s not fully reliable yet
✔ The workarounds genuinely help
❌ You’ll still run into issues from time to time

If you’re patient and stick to the “join the lobby first” rule, you can have solid co-op sessions in Anno 117. Plenty of players are doing exactly that.

But if you’re expecting the smooth, plug-and-play experience that Anno 1800 eventually became, it’s just not there yet. Multiplayer is functional, improving, and definitely playable — just not fully polished.

For now, think of it as “playable with rules” rather than “fire and forget.”