Reshade Bug with rFactor 2 in VR

Reshade: 6.3.3 (Standard Verson)
rFactor 2 Version: 1.1134
Issue: Reshade works well in VR but only in single player modes. Once you connect to any server, even to a LAN server, Reshade only works on the monitor and Reshade effects are no longer reproducible within the VR headset.

I tried older versions of Reshade without any luck however when installed Reshade 6.3.3 (version with full addon support even without installing any extra addons), it works well in multiplayer both in VR and in 2D. The only reason I do not want to keep the  addon supported verison of reshade due to risk of ban if used in online, hopefully the standard version gets fixed soon. Thank you.

After investigating the problem, I’ve identified that Reshade currently lacks native VR integration. The existing workaround relies on the third-party addon "Effect Runtime Sync", which mirrors standard screen-based Reshade effects to the VR headset. However, Reshade’s security protocols in multiplayer environments automatically disable all third-party addons, including this critical sync tool. This results in the complete deactivation of Reshade effects during multiplayer VR sessions.While this limitation has persisted into 2025, a community-developed solution exists: fholger’s OpenVR-modified Reshade fork . This version implements native VR support without requiring external addons and remains functional in multiplayer modes. Unfortunately, it’s built on an outdated Reshade codebase (circa 2022), leading to instability issues such as crashes during graphical setting adjustments or multiplayer server restarts.This highlights an urgent need for official native VR support in Reshade. Doing so would eliminate reliance on community fixes and ensure compatibility with multiplayer VR modes.   

ReShade has had a working native VR integration since version 5.0 (3 years ago), the fork you mention is years old before that was the case. (Which is kinda obvious considering the build with full add-on support works fine).
The only thing the "Effect Runtime Sync" add-on does is, as the name implies, synchronize the settings of multiple instances of ReShade, so that both the desktop instance and the VR instance always use the same settings (meaning you can control the VR instance by modifying the settings in the desktop instance and vice-versa, instead of having to explicitly change the settings of the VR instance in VR). The add-on is not necessary for VR functionality at all beside providing this convenience feature.

The standard build does have a safety feature that disables add-ons when there is network activity. This does not affect VR support, it only turns off the synchronization between desktop and VR instance of ReShade. You can still use it VR, just will have to configure it there directly (via ReShade entry in the SteamVR dashboard, or by configuring ReShadeVR.ini manually outside the game).

This is really helpful. Im coming at this from a different direction. I want to produce the reshade FX on the VR Compositor Mirror only.

Does this mean I can disable Effect Runtime Sync somehow?

Simply disable the "Effect Runtime Sync" add-on (via the checkbox next to the entry on the Add-ons page in the overlay).

Thanks so much for this!! Saved me huge headaches!