Yep, I had the same problem a while back with Prepar3D and TrackIR. Sure enough the solution was a simple at just "Run As Administrator". Glad that the fix was that easy.

 

I think you didn't read his post properly... for him the solution was to *NOT* "run as administrator"... so the opposite of your case.

I just experienced the exact same issue with TrackIR and P3d V3.4. After working correctly ever since I got this computer, all of a sudden today TrackIR would just stop responding via SimConnect in the middle of a flight (both green lights stayed on). TrackIR was still working correctly when viewed in the TrackIR app. I reinstalled all the SimConnect versions again and did a clean reinstall of the TrackIR software and that seemed to fix everything. I'm using the most recent version of the TrackIR software 5.4.2.

Jay is correct. On a fresh system without FSX Boxed installed we only have ESP simconnect installed with P3D. If we intend to use addons from the FSX era we must install the three legacy simconnects 60905, 61242, and 61259.

I only installed the SimConnect from "redist\Interface\FSX-SP2-XPACK" and I have no problem with TrackIR or other software.

Yes that's the one TIR uses. But you may come across other addons that use 61242 and even 60905. You'll see popular addon devs recommending you install all three, like PMDG.

 

The addon version is not an age thing it's a compatibility thing. 61242 works with all versions of FSX so many addons use that, but 61259 only works with SP2 so addons can work on P3D and FSX:SE by utilising 61259.

I only installed the SimConnect from "redist\Interface\FSX-SP2-XPACK" and I have no problem with TrackIR or other software.

This also immediately solved my problem of Track IR 5 not connecting with P3d v4.

The path to get there is:

Prepar3d v4 / redist / Interface / FSX-SP2-XPACK / retail / lib

then click execute the file: SimConnect.exe

 

and BINGO, it worked.