# FiveM License Key Error – Fix sv_licenseKey & IP Mismatch

FiveM license key error? Invalid key, Keymaster, server.cfg & Cfx.re account – fix step by step.

**Quick answer:** FiveM license key errors: **check key at keymaster.fivem.net**, set `sv_licenseKey` in **server.cfg** and match **server IP** with registered IP.

**If you landed here:** Console shows "Could not authenticate server license key", server won't start or players can't join.

## Error → fix

Symptom / logFix

Could not authenticate server license keyCheck key + IP on Keymaster

Invalid license keyCopy key without spaces

Key after server moveGenerate new key for new IP

## Related

- [FiveM won't start](/en/gameserver/fivem/server-startet-nicht)
- [FiveM won't connect](/en/gameserver/fivem/server-verbindet-nicht)
- [Install FiveM](/en/gameserver/fivem/installation)
*Products & ordering: [Order game server](https://nexorahost.com/category/gameserver-1) · Manage: [panel.nexorahost.de](https://panel.nexorahost.de) · [My account](https://nexorahost.com/account) · [nexorahost.com](https://nexorahost.com) (Frankfurt · 1 Tbit/s DDoS · 99.9% uptime)*