UEFN does not respond
Island Pilot goes through Epic Games’ official MCP server, which runs inside UEFN, on your computer. If the connection fails, the cause is most often a UEFN setting or an island different from the one expected.
Read the connection state
Section titled “Read the connection state”- Click the connection icon, at the top of the app.
- The Connexions (Connections) window opens. Look at the UEFN officiel (Official UEFN) line.
- After a fix, use the refresh button of this window.
When all is well, the line shows UEFN connecté · projet vérifié (UEFN connected · project verified). The Compiler Verse (Compile Verse) button is only usable at that point, and when no agent is working.
Check in order
Section titled “Check in order”- The right island. UEFN is open on the same island as the project chosen in Island Pilot.
- The two project options. In UEFN’s Project Settings, Python Editor Scripting and UEFN MCP Toolsets are enabled.
- The MCP server. In Edit › Editor Preferences › Agentic Workflows › Model Context Protocol, the server is started (Start Server button since UEFN 43.00), with its automatic start.
- The restart. After changing a setting, save your work and restart UEFN.
- The automatic connection. In Paramètres › Général (Settings › General), Connexion à UEFN (Connection to UEFN) section, Connexion automatique (Automatic connection) is turned on.
- The port. The default address is
http://127.0.0.1:8000/mcp. If you changed the port in UEFN, adapt the address in Store & connexions (Store & connections), then restart UEFN. - The launch. Island Pilot is launched from the Start menu, and not from another application. Otherwise, it cannot write UEFN’s settings at their real location. Paramètres › Diagnostic (Settings › Diagnostics) flags it on the Lancement (Launch) line.
The first-time setup is detailed in Connect UEFN.
The messages
Section titled “The messages”| Message | What it means | What to do |
|---|---|---|
| Connexion automatique désactivée. (Automatic connection disabled.) or Désactivé (Disabled) | The connection is off for this project | Turn on Connexion automatique |
| Handshake MCP HTTP impossible. Vérifiez l’URL, l’éditeur et l’authentification. (MCP HTTP handshake impossible. Check the URL, the editor and the authentication.) | Island Pilot cannot reach the server: UEFN is closed, the server is not started or the port differs | Follow the steps above |
| Connexion MCP expirée après 30 secondes. (MCP connection timed out after 30 seconds.) | UEFN did not respond in time | Check that it is not frozen or busy, then refresh |
| Le toolset Verse n’est pas disponible dans cet éditeur. (The Verse toolset is not available in this editor.) | The editor’s tools are not loaded | Check UEFN MCP Toolsets, then restart UEFN |
| UEFN connecté · identité du projet à configurer (UEFN connected · project identity to configure) | The link works, but the project is not confirmed | Open the same island in UEFN and select its folder in Island Pilot |
| Le projet ouvert dans UEFN ne correspond pas au chemin Verse de ce workspace. Action bloquée. (The project open in UEFN does not match the Verse path of this workspace. Action blocked.) | Another island is open in UEFN | Open the right island, or change project in Island Pilot |
| L’identité de l’éditeur ne correspond pas au projet attendu. Action bloquée. (The editor’s identity does not match the expected project. Action blocked.) | Same cause | Same solution |
| Un outil utilise actuellement l’éditeur. (A tool is currently using the editor.) | An agent is using it | Wait for the end of its step |
| Réglages d’UEFN introuvables sur ce PC : ouvrez UEFN une fois, puis réessayez. (UEFN settings not found on this PC: open UEFN once, then try again.) | UEFN has never been launched on this PC | Launch it once, then try again |
Island Pilot deliberately blocks any change while the open project does not match: this avoids changing the wrong island.
UEFN is busy
Section titled “UEFN is busy”An import, shader compilation, a Verse compilation or the launch of a game session can leave UEFN silent for a while. Island Pilot retries by itself.
If the message says UEFN ne répond toujours pas (UEFN is still not responding), check whether a window or dialog box in UEFN is waiting for your answer.
An action stays at an unknown result
Section titled “An action stays at an unknown result”If UEFN cuts out during an action, Island Pilot does not know whether it succeeded. It displays, for example, Appel MCP interrompu ou expiré. Résultat inconnu : inspectez l’état avant de réessayer. (MCP call interrupted or timed out. Result unknown: inspect the state before trying again.) and blocks new changes.
- Look in UEFN at what really changed.
- In Activité (Activity), on the action concerned, click Consigner une inspection (Record an inspection).
- Describe what you found in Résultat de votre inspection (Result of your inspection), then click Enregistrer mon constat (Save my finding).
You can also ask an agent to reread the real state and record that finding. Do not rerun the action blindly: it might be applied twice.
Still stuck
Section titled “Still stuck”Run Paramètres › Diagnostic, then write to us with the result. See Logs and diagnostics.