Why your modded Conan Exiles server crashes on startup (and how to fix it)

If your heavily-modded Conan Exiles server starts, churns for a few minutes, and then falls over with an out-of-memory error even though the panel shows most of your RAM unused, this is the guide for you. It is one of the most confusing failures Conan throws, because the error it prints is not the error you actually have.

This applies to Conan Exiles Legacy (UE4) servers. The exact log lines below only appear on the UE4 build. If you are on Conan Exiles Enhanced (UE5) and the server will not boot, that is a different playbook: see the Enhanced update guide and Enhanced won't launch. For everything else Conan, the general troubleshooting guide is the catch-all.

The symptom

• The panel says the server is running, but it never actually comes online and nobody can join.
• It sits there for several minutes (often around ten), then the process exits.
• In the log, near the end, you get something like Ran out of memory ... allocating 261593038848 bytes (or some other absurd number in the hundreds of billions). Your plan has nowhere near that much RAM, and the panel's resource graph was barely ticking over when it died.
• Restarting does not help. It does the exact same thing every time.
• It usually starts after a mod update, after the Conan Exiles Enhanced split in May 2026, or seemingly out of nowhere on a big mod list.

The "out of memory" message is a red herring. You are not actually out of memory.

What is really happening

On boot, Conan reads your mod list from ConanSandbox/Mods/modlist.txt and loads each mod's .pak file. If a mod is listed but its .pak is missing from disk, the engine does not fail cleanly and tell you which mod is gone. Instead it tries to allocate an impossible amount of memory in one go, hundreds of gigabytes, and dies with "out of memory" after hanging for a while.

So the real problem is almost always a mod file that should be on disk and is not. There are two common reasons one goes missing:

1. A bulk "update everything" pull that did not finish. Large collections are several gigabytes, and if the batch times out or one item in it fails, you can end up with some paks downloaded and others not while the mod list still references all of them.
2. The early-May 2026 mod removals. Around the Enhanced launch Steam temporarily pulled a wave of Conan Workshop mods. Most have since been reinstated, so a mod that would not download back in May usually downloads fine now.

Confirm it from the log first

Do not guess. Open Log Viewer in the panel sidebar (or grab the latest ConanSandbox.log over SFTP, port 8822) and look for three things.

1. Confirm you are on Legacy/UE4. Near the top:

LogInit: Engine Version: 4.15.3-1934160+ue415-dw-osl

4.15.3 means Legacy/UE4, and this guide applies. If it says 5.x you are on Enhanced and should use the Enhanced guides linked above.

2. Find the missing mods. These lines name them directly:

LogModManager:Error: Mod pak file: .../ConanSandbox/Mods/Emberlight.pak does not exist

Every does not exist line is one mod whose file is gone. Note them all down.

3. Confirm the bogus allocation. Near the very end:

LogMemory:Warning: Freeing 33554432 bytes from backup pool to handle out of memory.
...
Ran out of memory in app state 'StartPlay' allocating 480107692032 bytes

A giant allocation number plus your real memory use being low is the signature. That combination is the missing-mod problem, not a plan-size problem. Buying more RAM will not fix it.

Fix part 1: get the missing mods back

1. From the log, you have the list of mods whose .pak does not exist.
2. In Mod Manager, reinstall or update those mods one at a time. Do not reach for a blanket "reinstall the whole collection" or "update everything" action. That bulk pull is the thing that left you half-installed in the first place, and it will often fail in the same place again. Adding mods back individually is slower but reliable, and big mods can be several hundred megabytes each, so give each one a minute. The Log Viewer shows the download progress.
3. If one specific mod refuses to download, open its Steam Workshop page. If it shows "This item has been removed from the community", it is delisted and the server cannot pull it. Most of the May 2026 removals have been reversed, so this is rare now, but if you hit a genuinely delisted mod you have two options: get the .pak from someone who is still subscribed to it (their copy is in their local steamapps\workshop\content\440900\ folder) and drop it into ConanSandbox/Mods/, or remove that mod from your list.
4. Restart and re-check the log. The does not exist lines should be gone.

While you are in there: check the mod list itself

Occasionally the failure is not a missing download but a garbled modlist.txt. We have seen a line where two mods got fused together with a stray character, for example ModAdmin.pak*SvS2.pak, which makes the server hunt for a file that cannot exist. Open ConanSandbox/Mods/modlist.txt in File Manager (or over SFTP) and make sure every line is exactly one .pak, one per line, with no stray characters and no two mods on the same line. Delete any line that points at a mod you no longer have installed.

One related warning Inflexion call out: do not rename mod pak files. A renamed pak silently fails to load even when the list looks correct. Keep the filenames Steam Workshop gives them.

Fix part 2: it still crashes after every mod is present

If the log now shows zero does not exist lines and the server still hangs and then dies, but the crash now happens during the world-loading stage (you will see a run of Persistence: Loading mod controller lines, then a long pause, then the same out-of-memory number), the problem has moved from your mod files to your saved world.

This happens when the world save still contains data from a mod that is no longer installed. The tell in the log is a line like:

LogStreaming:Error: Couldn't find file for package /Game/Mods/Level_700/Level_700_Controller

for a mod that is not in your current list. The world is trying to rebuild objects whose mod code is gone, and that can wedge the load the same way a missing pak does.

Confirm it is the save, not the mods, with one test. Stop the server, then in File Manager rename your world database aside:

• Exiled Lands: rename ConanSandbox/Saved/game.db to game.db.bak (also rename game.db-wal and game.db-shm if they are there).
• Isle of Siptah: the file is dlc_siptah.db instead.

Start the server. If it boots cleanly on a fresh, empty world, your mods are fine and the save is the culprit. Rename the files back afterwards, this was only a test, you do not want to keep the empty world.

To recover, do not keep booting the broken save:

1. Stop the server.
2. Open Backup Manager (or Cloud Restore) in the sidebar and pick the most recent backup taken before the trouble started.
3. Restore it, then make sure every mod that world expects is actually installed, reinstall the ones that were removed, or accept that their placed content is gone.
4. Start the server.

Removing a mod always deletes the items and structures it added from the world. That part is normal Conan behaviour. The crash only happens when the save is loaded against a mod set that is partly missing.

If you would rather not do the rename-and-restore yourself, open a ticket and we will run it for you.

How to stop it happening again

• The big one: after a Steam push, update your mods a few at a time and give each one a minute to finish, rather than firing off a single "update everything" and walking away. That bulk operation is exactly what leaves a big list half-installed.
• Keep modlist.txt tidy. One pak per line, nothing pointing at a mod you have dropped.
• Take a backup before you touch mods at all. A quick Backup Manager snapshot, or pull game.db down over SFTP, gives you a clean rollback and costs about ten seconds.
• If you are deliberately running a UE4 mod stack, ask us to pin your service on the Conan Exiles Legacy branch. That stops a stray base-game update from migrating you to Enhanced (UE5) and breaking every UE4 mod at once. The Enhanced update guide covers the Legacy branch.
• A daily scheduled restart via Scheduled Tasks keeps memory healthy in general, and it is good practice on any busy Conan server regardless of mods.

If you would rather we just fixed it

We are around 24/7 and we would much rather hear from you early than have you wrestle a 60-mod list at 2am. Open a ticket from the LOW.MS Control Panel and include:

• The last 50 or so lines of your ConanSandbox.log (Log Viewer, or over SFTP).
• Which mods you recently added, updated, or removed.
• Whether you changed anything just before it started crashing.

With the log in hand we can usually tell which mod is missing in a couple of minutes, restore it, and get you back online.