FiveM

OneSync not enabled / entity limit exceeded (FiveM)

OneSync is FiveM's server-side entity sync system. Without it, the default entity limit is 64 entities per player, and certain resources (mainly scripted vehicle spawning, NPC population systems, and large event maps) hit that ceiling immediately. Resources that require OneSync log 'OneSync is not enabled' on startup and refuse to run. The fix is a two-line server.cfg change — assuming your license key supports it.

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How to fix it

  1. 1

    Add OneSync to server.cfg

    Add these two lines near the top of server.cfg, before any ensure lines: set onesync on set onesync_population true 'onesync on' enables full OneSync (infinity mode, no entity cap). 'onesync legacy' is the older compatible mode — use it only if you have resources that break with full OneSync.

  2. 2

    Verify your license key supports OneSync

    Free license keys from keymaster.fivem.net support OneSync, but your FXServer version must be recent enough. Run 'version' in the server console — you need FXServer build 4934 or later. If you're on an older build, update FXServer before enabling OneSync.

  3. 3

    Restart FXServer completely

    OneSync is read at startup. A live 'restart' of resources doesn't apply it — you need a full FXServer restart. Stop the process and start it again. Check the console for 'OneSync: on' in the startup banner.

  4. 4

    Update resources that were checking for OneSync at runtime

    Some older resources have a hardcoded check: if GetConvar('onesync_enabled') ~= '1' then error('requires OneSync') end. Make sure the convar name matches your setting. The correct convar is 'onesync' (not 'onesync_enabled'). Check the resource's fxmanifest or main script.

Alternative causes

These can produce the same error message — worth ruling out if the steps above don't resolve it.

onesync set to 'off' by mistake

A previous server admin or template may have explicitly set 'set onesync off'. This overrides any other setting. Search server.cfg for 'onesync' and make sure there's no contradicting 'off' line below your 'on' line.

Running a txAdmin recipe that doesn't enable OneSync

Some txAdmin recipes and setup templates don't enable OneSync in the generated server.cfg. After provisioning, open server.cfg and add the OneSync line manually before starting resources that need it.

Frequently asked

What's the difference between 'onesync on' and 'onesync legacy'?

'onesync on' is full OneSync (infinity mode) with no entity cap and full server-side entity management. 'onesync legacy' is the older pre-infinity mode — 64 entities per player bucket, but compatible with resources that assume the old entity model. Use 'on' for new servers.

Does OneSync affect server performance?

Yes — positively for player counts above 32 (less network traffic per player) but with more CPU overhead for the entity tracking system. For small servers (< 30 players), the difference is negligible.

Can I disable OneSync to fix a specific resource?

You can, but it will break all resources that require it. The right fix is finding which resource breaks with OneSync and updating or replacing it, not disabling a core feature for all other resources.

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Last reviewed 2026-06-15. If a step is wrong or out of date, tell us — we'll fix the article and the auto-pattern at the same time.