Fix FSUIPC not connecting in MSFS, FSX, Prepar3D or FS2004. Check the correct version, SimConnect, permissions, security software and logs.
FSUIPC is normally not connecting because the installed FSUIPC generation does not match the simulator, the module or FSUIPC7 process failed to start, SimConnect is unavailable, or Windows security blocked it. Install the correct build, start it at the right time, match privilege levels, then use its log to identify the failed stage.
The diagnosis differs between Microsoft Flight Simulator 2020 or 2024, FSX, Prepar3D and FS2004. FSUIPC7 is an external Windows application for MSFS, while older simulator generations generally load FSUIPC as an in-simulator module. Standard FSUIPC does not connect to X-Plane or DCS, and it cannot be installed on an Xbox or PlayStation console.
What does the FSUIPC connection symptom mean?
| Symptom | Likely cause | First check |
|---|---|---|
FSUIPC7 remains on Waiting for MSFS | MSFS is not ready, SimConnect failed, or the wrong FSUIPC7 build is installed | Load a flight to the cockpit and inspect the FSUIPC7 log |
| FSUIPC is missing from the FSX or Prepar3D Add-ons menu | The module did not load, was rejected, or does not support that simulator generation | Check the simulator and FSUIPC module logs |
| FSUIPC says it is connected, but another program does not | The fault is with that program's FSUIPC interface, configuration or network connection | Confirm the FSUIPC status before changing SimConnect |
| WideClient keeps waiting for a connection | WideFS configuration, local networking or the firewall is blocking the remote client | Test on the simulator PC before troubleshooting the network |
| Aircraft switches work, but advanced controls do not | The MSFS WASM component or aircraft-specific variables may be unavailable | Do not mistake a WASM problem for a basic FSUIPC connection failure |
How do I fix FSUIPC not connecting?
- Confirm the simulator and FSUIPC generation. Do not install the newest-numbered package blindly: each generation supports particular simulators. Use our FSUIPC package and simulator compatibility listing, then remove obsolete copies rather than leaving several DLLs or installations active.
- Start the simulator cleanly. Disable unnecessary add-ons for the test, launch the simulator and load a simple default aircraft at an airport. For MSFS, start FSUIPC7 manually if it did not auto-start. Seeing
Waiting for MSFSbriefly before the simulator is ready is normal; seeing it after entering the cockpit is not. - Run both programs at the same privilege level. The safest arrangement is normally to run MSFS and FSUIPC7 as standard Windows applications. Running one as administrator and the other normally can interfere with input handling, companion programs and automatic startup.
- Check security software. Look for a quarantined FSUIPC executable or DLL and allow the actual FSUIPC installation directory through antivirus protection and the Windows firewall. Do not disable security software globally. Protected-folder controls can also stop FSUIPC from writing its configuration or log.
- Read the fresh log. Close the simulator, preserve or rename the previous log, reproduce the failure once, and exit normally. The FSUIPC installation or Modules directory should then contain a log showing the installed version, simulator detection, SimConnect status and module-loading errors. The first connection or loading error is usually more useful than later repeated messages.
- Reinstall only after identifying the layer that failed. Back up the FSUIPC configuration and profile files first. Run the correct installer again and allow it to repair startup entries or module registration; copying an old DLL manually into another simulator is a common cause of version conflicts.
What should I check in Microsoft Flight Simulator?
FSUIPC7 must establish a SimConnect session with the PC edition of Microsoft Flight Simulator 2020 or 2024. If it never gets beyond Waiting for MSFS, follow our detailed FSUIPC7 startup, installation and log checks.
A damaged simulator installation, an incompatible FSUIPC7 build or a custom SimConnect configuration can prevent the session from opening. Remove or temporarily rename custom SimConnect.cfg and SimConnect.xml files only if you know they were added for a networked client; do not create either file for an ordinary local installation. Our guide to checking and repairing the MSFS SimConnect layer covers that failure separately.
The optional FSUIPC WASM module is not required for the initial FSUIPC7-to-MSFS connection. It is used for access to aircraft-specific local variables, events and presets. If FSUIPC7 reports a simulator connection but a complex aircraft control does nothing, investigate the WASM component and that aircraft's variable support instead of reinstalling SimConnect.
Why is FSUIPC missing in FSX or Prepar3D?
If FSUIPC is absent from the simulator's Add-ons menu, its in-process module did not load. Check that the installed FSUIPC generation supports the exact FSX or Prepar3D generation, then review the module and simulator loading logs for a rejected DLL, duplicate entry or invalid installation path.
On the first launch, FSX may ask whether the module and its publisher should be trusted. Rejecting that prompt can leave the DLL disabled. Reinstalling the matching package can restore the loader entry, but retaining an incompatible DLL in the Modules folder may cause the same failure again.
What is different in FS2004?
FS2004 requires the legacy FSUIPC 3 line rather than FSUIPC7 or a modern Prepar3D package. Placement in the Modules folder, trust prompts and conflicts with older copies are covered in our FS2004-specific FSUIPC installation procedure.
Why does my add-on say FSUIPC is disconnected when FSUIPC is working?
If the FSUIPC window or simulator menu confirms a connection, do not keep repairing the simulator link. Restart the companion program after FSUIPC is ready, check that it is configured for the correct simulator and remove any obsolete path, host name or port retained from an earlier installation.
For a program running on another computer, FSUIPC normally remains on the simulator PC while a compatible network client communicates across the local network. Test the program on the simulator PC first. If that works, check WideFS or the add-on's own networking method, the selected server address and private-network firewall permissions.
Does FSUIPC need a paid registration to connect?
No. A missing registration is not the cause of a basic simulator connection failure. Registration unlocks applicable user features, but installing a licence will not repair SimConnect, load a rejected DLL or correct an incompatible FSUIPC generation.