Fix GSX Pro not detecting your SimBrief ID or showing ‘username missing’ in MSFS 2024, with checks for the right login, flight plan and Couatl.
GSX Pro usually fails to detect SimBrief because the SimBrief Username box in its own settings is blank or contains a Pilot ID, email address or old username. In Microsoft Flight Simulator, including MSFS 2024, enter the exact identifier named by GSX, save it, generate a briefing and restart Couatl.
GSX SimBrief username missing: which identifier does it need?
If GSX reports that the SimBrief username is missing, it has no usable username saved in its own settings. A working SimBrief login in an aircraft tablet or the MSFS 2024 EFB does not automatically configure GSX.
Open the GSX Pro settings from its in-simulator menu and read the field label carefully:
- If it says
SimBrief Username, enter your exact SimBrief account username. - If it explicitly asks for a
Pilot IDorUser ID, enter the numeric identifier shown in your SimBrief account details. - Do not substitute your email address, account display name, Microsoft account name or a number copied from the flight plan.
A mistake we see constantly is copying the numeric Pilot ID from an aircraft EFB into GSX’s username field. Different add-ons request different identifiers, so a value that works in one aircraft is not automatically correct for GSX.
Type the value manually rather than pasting it. This removes leading spaces, trailing spaces and hidden characters. If you changed your username, moved to MSFS 2024 or reinstalled GSX, replace the saved entry and restart Couatl.
What does the GSX SimBrief error mean?
The exact message usually separates an account-setting problem from a missing flight plan or blocked connection.
| Symptom | Likely meaning | First check |
|---|---|---|
| SimBrief username missing | The GSX setting is blank, invalid or was not saved | Enter the username in GSX’s own settings |
| User not found | Wrong identifier type, misspelt username or old account value | Compare the field label with your SimBrief account details |
| No flight plan or briefing found | The account was recognised, but it has no suitable generated OFP | Generate a new plan on the same account |
| Request failed or timed out | Couatl is not responding or the online request is being blocked | Restart Couatl and check VPN, firewall and antivirus filtering |
| Only one aircraft fails | The GSX account is probably valid; the aircraft integration or profile is the better suspect | Repeat the test with a default aircraft |
How do I fix GSX Pro not detecting SimBrief in MSFS 2024?
Fix the GSX account field first, then check the briefing, Couatl service and internet connection; reinstalling should be the last resort.
Read the complete error. A missing username, unknown user and missing briefing are three different faults. Do not regenerate plans repeatedly when GSX is explicitly saying that its username field is empty.
Re-enter the identifier in GSX settings. Use the username when the field says
SimBrief Username; use the numeric ID only when GSX explicitly requests it. Save the setting, close the GSX menu and reopen it to confirm that the value remained stored.Generate a fresh operational flight plan. Complete the plan and use SimBrief’s generate or dispatch action. Merely editing or saving a route does not necessarily create the OFP that GSX retrieves.
Update GSX Pro and its components together. Run the supplied GSX installer or updater, especially if the failure began after an MSFS 2024 update. The in-simulator menu may still open even when an older helper component can no longer complete the online lookup.
Restart Couatl. Use the GSX restart control where available, or exit and relaunch the Couatl helper. If the setting still is not reloaded, close Microsoft Flight Simulator completely and start it again; returning to the main menu may not reset the external helper.
Check connection filtering. Allow GSX and Couatl-related processes normal internet access through the firewall and antivirus software. Briefly disconnect a VPN or filtered connection as a test, then re-enable protection and create an appropriate permission rather than leaving security disabled.
Run a clean comparison. Use a newly generated plan, a default aircraft and a default airport. If the same account error appears there, concentrate on the GSX setting, Couatl, the network connection or the installation. If the clean test works, the original aircraft or GSX profile is involved.
Does the MSFS 2024 EFB SimBrief login configure GSX?
No. The MSFS 2024 EFB and GSX Pro store their SimBrief account links separately, so signing into one does not populate the other.
Use the same SimBrief account in both, but enter each identifier in the format its field requests. Importing the route into the simulator is not required for GSX to recognise your account; it is useful for confirming that a generated plan exists and that the EFB is using the intended account. Our walkthrough of checking and importing a SimBrief plan through the MSFS 2024 EFB covers that part of the process.
Do not assume that an MSFS 2020 GSX setting has carried into MSFS 2024. Re-enter and save the username in the GSX installation used by the new simulator.
Why does GSX find my account but not my flight plan?
If GSX accepts the user but cannot find a briefing, the identifier is probably correct and the problem has moved to the flight-plan stage.
- Make sure the plan was fully generated, not left as an edited route.
- Confirm that it was generated under the same SimBrief account configured in GSX.
- Generate a fresh OFP if GSX is retrieving old passenger, cargo or route data.
- Restart or refresh GSX after replacing the plan if it continues to show cached information.
A stale briefing does not make a valid username invalid. It explains old or missing flight data, while username missing points directly to the GSX account setting.
What if SimBrief fails only with one aircraft?
A genuine GSX username problem normally follows every aircraft because the SimBrief identity is stored by GSX rather than by an individual aeroplane.
If a default aircraft works, compare the affected aircraft’s EFB account, loading options and GSX profile. The aircraft may be signed into another SimBrief account or may require its own refresh before it displays the same plan. If the problem is confined to the Fenix, our Fenix A320-specific troubleshooting checks help separate an aircraft fault from a GSX account failure.
Repair or reinstall GSX only when the correct identifier fails across multiple aircraft after an update, a Couatl restart and a clean network test. Do not delete custom airport or aircraft profiles as the first fix; they are not normally responsible for a missing SimBrief username.