# Stay in Tarkov (SPT/Fika) Troubleshooting (/docs/stay-in-tarkov/troubleshooting) import { Step, Steps } from 'fumadocs-ui/components/steps'; Most SPT/Fika issues fall into a few buckets. Find your symptom below. A Mod Isn't Loading [#a-mod-isnt-loading] The mod is for SPT 3.x but your server is SPT 4.0 [#the-mod-is-for-spt-3x-but-your-server-is-spt-40] **Symptom:** You installed a mod, but its features never appear. The **Console** shows a line like: ``` No Assemblies found in path: /home/container/SPT/user/mods/ ModLoader: loading: 1 server mods ``` **Cause:** SPT **4.0** changed how server mods work. A 4.0 server loads compiled **.NET assemblies** (`.dll` files) from `user/mods//`. Older **3.x** mods are TypeScript/Node (a `package.json` with `mod.js`/`mod.ts`) and contain no `.dll`, so a 4.0 server reports "no assemblies" and silently skips them. **Fix:** Install the **SPT 4.0-compatible** build of the mod. On the mod's page, confirm it lists **SPT 4.0** support before installing. A 3.x-only mod will never run on a 4.0 server, no matter where you place it. The mod is in the wrong folder [#the-mod-is-in-the-wrong-folder] **Symptom:** The mod doesn't load and there's no error about it at all. **Fix:** Server mods go in `user/mods/`, each in **its own folder**. Some mods also ship a **client-side** part that each player installs in their own `BepInEx/plugins` folder — the server copy alone won't enable it. Check the mod's page for client requirements, and see [Installing Mods](/docs/stay-in-tarkov/installing-mods). You didn't restart after installing [#you-didnt-restart-after-installing] **Fix:** Mods are loaded at startup. **Stop and start** (or restart) the server after adding or removing a mod, then check the **Console** for load messages or errors. Players Get Kicked on the Mod Check / Client Mods Out of Sync [#players-get-kicked-on-the-mod-check--client-mods-out-of-sync] **Symptom:** A player can't join because their installed client mods don't match the server's. **Fix:** Open the **SPT Mods** tab in the panel and use **Enable Client Mod Sync**. This installs a sync mod on the server so that, when players connect, their client mod set is checked and kept aligned with the server automatically — no hand-matching of files. Players still install their own SPT/BepInEx client, but the mod list is kept in step for them. The Server Won't Start [#the-server-wont-start] **Symptom:** The server stops right after starting, or never reaches "server started." **Fix, in order:** 1. **Read the Console.** SPT prints the exact mod or config that failed. The last lines before it stops are the clue. 2. **Suspect a recently added mod.** If it started failing right after you installed something, remove that mod's folder from `user/mods/` and try again. 3. **Check your config edits.** A malformed value in a `.json`/`.jsonc` config (a missing comma or bracket) can stop the server. Undo your last config change. 4. **As a last resort, reinstall.** For heavily-modded setups that won't recover, back up `user/profiles/` first, then reinstall from the panel and re-add mods one at a time. > 💡 **Tip:** Back up `user/profiles/` before any reinstall — that's where all player progress lives. See [Manage Profiles](/docs/stay-in-tarkov/manage-profiles). Can't Join a Friend's Raid ("Unable to Connect") [#cant-join-a-friends-raid-unable-to-connect] You can log in and see each other, but joining a raid fails. This is almost always a **client-side Fika/NAT setting**, not a server fault. Fika works in two parts: the **SPT server** handles logins and profiles (this working is why you can *see* each other), while the **raid itself is peer-to-peer** — one player hosts and the others connect directly to them. New SPT/Fika servers on XGamingServer have **NAT punching enabled automatically**, so the fix is on each player's game client. Every player (host and joiners) should set this in the Fika client config (press **F12** in-game, or edit `BepInEx/config/com.fika.core.cfg`): Clear "Force IP" [#clear-force-ip] Make sure **Force IP** is **empty**. Remove any server IP you previously typed in. Enable "Use NAT Punching" [#enable-use-nat-punching] Turn **Use NAT Punching** **ON** so the client discovers the raid host through the server automatically. Disable "Use UPnP" [#disable-use-upnp] Turn **Use UPnP** **OFF** — it conflicts with NAT punching and isn't needed. Remove manual port forwards [#remove-manual-port-forwards] Undo any port-forwarding rules or UDP port changes you added for Tarkov/Fika. Then **fully restart** every player's game and try again. If one specific player can never host (some strict/CGNAT networks block P2P), have someone else host instead. See also [Connect to Your Server](/docs/stay-in-tarkov/connect-to-your-server). Headless Client Problems [#headless-client-problems] A **headless client** is a second SPT game client a player runs on their **own machine** to host raids — it doesn't run on the game server. * **Create one from the panel:** open the **Fika Admin** tab → **Headless Clients** → **New profile**, then load that profile ID into the headless SPT client. See [Manage Your Server](/docs/stay-in-tarkov/manage-your-server). * **A headless client is unstable or crashing:** headless clients are sensitive to mods. Test with a minimal mod set, and make sure the headless client's mods match the server. Performance / Desync [#performance--desync] **Symptom:** Stutter, rubber-banding, or AI desync during raids. **Cause:** SPT raids are largely **single-threaded**. Raw core count matters less than **single-thread performance**. **Fix:** Keep your mod count reasonable (AI-heavy mods are the biggest cost). In Fika co-op the **raid host's** machine also carries load for that session, so have your best-connected player host. Still Stuck? [#still-stuck] Open a ticket from the [XGamingServer panel](https://panel.xgamingserver.com) or ask in our [Discord](https://discord.xgamingserver.com/). To help us help you fast, include: * The **Console** output from a fresh start-up. * The exact **SPT and Fika versions** shown in the console. * Whether **all** players are affected or just one.