after hours of investigation, removal of mods, etc. we finally discovered the source of the problem: the TDS GNS 750 tray app was running and needed to be updated.
thanks to everyone who helped investigate this impossible problem.
Interesting details:
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I had removed ALL mods from Community and had uninstalled all the mods from marketplace official that raised conflicts in the simstaller tool from Parallel 42. The simstaller scan was completely clean, yet the error persisted.
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I had forgotten that I had the TDS autolaunch via exe.xml on sim startup to save starting it each time manually.
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I didn’t realize that the TDS app needed an update.
It appears that there were no javascript overrides from other mods involved in this error. Instead, my guess is that the TDS tray app is using SimConnect to implement a handshake using AP events. When it misinterpreted my AP reengage as a handshake from the 750, it may have sent an unknown pattern of rapid AP events to “establish” connection to the AP in case the user is running a TDS GNS 750. No one expected this interaction, although WT did recognize it as an “old bug” they thought TDS had fixed.
The TDS system consists of 3 components: a tray app, a JS mod in Community, and the Garmin trainer software for the 750 outside the sim. The tray app needs to watch for the JS mod “turning on”, at which point it starts a Garmin 750 process in the background and sends that display to the JS mod in aircraft that support the TDS 750 for rendering in the virtual cockpit.
What was completely unexpected was that the JS mod was uninstalled and the aircraft being tested (Asobo C172 steamgauge) did not use the 750 at all. That leaves the TDS tray app which was apparently injecting simevents that hung the AP under certain circumstances.
When we removed the TDS tray app, everything worked. I then checked the TDS app for updates, and found that it was behind by several versions. (This is why my other request for managing mod updates is so important.)
Lastly, I want to reflect on the amount of pain involved in debugging these dependencies. I don’t expect devs to know every combination, but likewise users shouldn’t be expected to try every combination of system configuration to isolate the problem.
What didn’t work:
- telling me I wasn’t using the AP correctly without seeing what I was doing
- “whatabout-ism” involving every possible component of the system, even down to windows install
- lack of awareness that not everyone’s system in Windows is the same, and that’s ok, and it’s NOT automatically a cause.
What did work:
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streaming/video capture of the actual problem. there were 1000 details missed in text. we kept talking past each other. sharing the video was a real breakthrough in allowing people to see and agree on the ground state.
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debugging a chain of evidence rather than “guessing”. it’s ok to have hunches, but then follow them up and actually PROVE the relation exists.
Some of these points are on the user side (like screen recording problems) and some are on the dev side (like proving instead of guessing). Some may be on the platform (Asobo) side: if we had a tool showing us where Simconnect messages were coming from, we might have instantly discovered that the TDS tray app was reacting to the AP reengage and sending unexpected messages to the AP causing it to hang.
It may help if TDS put a line in their user manual saying “the TDS app should only be run if you are using the TDS. unintended side-effects may occur if you run the app with other planes/avionics.”
Earlier I had also tried a mod fix and an unpublished fix from BKSQ in the justflight forums. neither of these had any effect on my issue and were unrelated.
The problem began back in November, total time spent debugging and triaging was probably 6-7 hours total. I fly Cessna Sundays with EasternHops, so every Sunday at least I would encounter this problem with the AP. I stopped using it and avoided the affected aircraft.
There may not be many people using TDS, but maybe this will help any that are and have a similar problem. Next time TDS will be the FIRST thing I check rather than uninstalling everything. 