Sim freeze when using vPilot

Hi everybody,

Almost everytime when I fly online on VATSIM using vPilot (last version) and new SU4, I got sim freeze. I’ve been able to confirm the behaviour with a test flight and setting Traffic to appear at 40nm range. And guess what, at 40nm inbound EGLL sim freezed (maybe too much traffic loaded at once, can’t offload old traffic vs new one etc).

I did the same flight online 3 times, with 3 differents distances 25-50-100, and again at exactly 25-50-100 nm of EGLL, I had sim freezing. When flying offline, no freeze.

Anyone is also experiencing this issue (I am mainly flying fenix) as well with new SU4 ?

9800X3D, 5090, 64GB DDR5, Windows 11.

Does this only happen there?

Nope randomly. Sometime during cruise, sometimes on approach, never on ground though.

Never had any freeze when flying offline.

If you remove the model matching set(s) you use does it still happen?

Affirm, with and without .vmr file.

Please make sure to run the IVAO software as Administrator.


Do not let it start automatically with MSFS.
Launch the IVAO software manually, as Administrator, once your aircraft is already at the airport.

Hi thanks for your reply.

I am not using IVAO but VATSIM. I guess I might give a try to IVAO as well to benchmark against vPilot.

I’m really sorry for the confusion. I had two tabs open, and instead of replying to the IVAO-related topic, I accidentally posted in your VATSIM thread. My apologies for the mix-up.


SU4 beta is currently known to cause issues with communication between the sim and 3rd party software. Unfortunately, this is not something you can fix on your side - it’s a problem related to the SU4 beta itself.

However, I recommend checking the VATSIM forums, as someone else may have encountered the same issue and found a workaround.