Fix the PMDG FMC INVALID RTE error by checking route format, company-route files, AIRAC data, waypoints, airways and procedures.
The PMDG FMC “INVALID RTE” error means the CDU cannot parse or validate the route it was given. Clear the message, confirm the origin and destination, load the correct PMDG route format, match the flight planner’s AIRAC cycle to the FMC, then remove or replace the first rejected airway, waypoint or procedure.
Across PMDG aircraft in Microsoft Flight Simulator (MSFS), Prepar3D and FSX, the controls and import methods vary by product. The point at which INVALID RTE appears is the strongest clue to the fault.
What triggers INVALID RTE in a PMDG FMC?
INVALID RTE is triggered when the FMC rejects the route as a whole or cannot connect one of its segments using the installed navigation database.
| When the error appears | Likely cause | Best first check |
|---|---|---|
| After entering a company-route name | Wrong route identifier, incompatible file format or a file saved for another PMDG product | Confirm the exact company-route identifier and PMDG-specific export format |
| During an aircraft route request or import | AIRAC mismatch, malformed export or unsupported custom waypoints | Regenerate the route for the correct aircraft and navigation cycle |
| While entering an airway | The entry fix or exit fix is not on that airway in the FMC database | Enter the route one VIA/TO segment at a time and identify the rejected pair |
| After choosing a departure or arrival | The runway, procedure or transition does not connect to the en-route section | Remove the procedure temporarily and select a compatible transition in the CDU |
How do I clear the PMDG INVALID RTE error?
The fastest reliable fix is to reduce the flight plan to a basic valid route, then add each airway, waypoint and procedure separately.
- Note which action caused the message. Press
CLRto dismiss the scratchpad warning. This clears the message, not the faulty route entry, so check the last file, airway, waypoint or procedure you selected. - Verify ORIGIN and DEST. Use the four-letter airport identifiers recognised by the FMC. If those fields were completed before an import, they must agree with the imported route; changed or retired airport identifiers can also cause a mismatch.
- Rebuild the smallest valid route. Before departure, create a clean route containing the origin, destination and first en-route fix. Add subsequent segments as VIA/TO pairs. For a direct leg, enter the next fix as a direct waypoint rather than typing
DCTinto the airway field. Our airliner FMC route-entry workflow covers the correct sequence and activation steps. - Use the correct PMDG route format. A generic simulator
.plnfile cannot be fixed by renaming it.rte. Enter the saved company-route identifier rather than an operating-system path or a complete ATS route string inCO ROUTE. Also check for accidental names such asroute.rte.txt. For the MSFS 737, follow our PMDG 737 SimBrief import and route-file checks. Local file copying is unavailable on consoles, so use the aircraft’s supported import function or enter the route manually. - Match the AIRAC cycles. Check the cycle shown on the FMC IDENT page against the cycle used to generate the flight plan. Re-export against the FMC’s installed cycle, or update the aircraft’s navigation data and then regenerate the route.
- Leave procedures out temporarily. Load the en-route section first, then select the runway, SID, STAR and transition from the FMC’s own database. Our guidance on choosing compatible SIDs, STARs and transitions explains how to avoid stale runway and procedure links.
- Activate and inspect the route. Select
ACTIVATEandEXECwhere required by that PMDG model, then examine the LEGS pages. If the error returns immediately after one new entry, that entry is the culprit.
Do not paste an entire space-separated flight-plan string into CO ROUTE. That field normally expects a saved route identifier, while manual airways and fixes belong on the route pages.
Can an AIRAC mismatch cause INVALID RTE?
Yes, an AIRAC mismatch can cause INVALID RTE when the planned route uses navigation data that the PMDG FMC does not contain.
- An airway may have changed, while its planned entry or exit fix is no longer part of it.
- A waypoint may have been renamed, removed or assigned a different identifier.
- A runway, SID, STAR or transition may not exist in the installed cycle.
- A planner-generated custom or oceanic waypoint may use notation that the particular PMDG model does not accept.
If the scratchpad instead identifies one fix as NOT IN DATABASE, troubleshoot that specific identifier using our FMC navigation-database error checks. A missing fix points towards navigation data or spelling; immediate rejection of an entire company route points more strongly towards its file, format or identifier.
Reinstalling the aircraft should be a last resort. Consider repairing its navigation data or installation only when multiple known airports and waypoints are missing, or even a simple manually entered route fails. One rejected airway from an older flight plan does not indicate a damaged PMDG installation.
Why does the route load but show a discontinuity?
A route discontinuity is not the same as INVALID RTE; it means two otherwise accepted legs have not been connected.
This commonly occurs between the en-route section and a SID or STAR, after a vector leg, or when the FMC has selected the wrong waypoint from several sharing one identifier. Use PLAN mode and step through the LEGS pages where the PMDG model supports it, checking for an unexpected turn or a waypoint on the wrong continent.
Close a discontinuity only when the next leg is the one you genuinely intend to fly. A discontinuity after a vector may be deliberate, and deleting it blindly can create an unsafe direct leg. Once the route is coherent, execute the modification and confirm that the active route and navigation display agree.