**Hi everyone,**

I recently migrated to NixOS from Arch Linux. I'm trying to install the Arknights Endfield client via the Heroic Games Launcher, but the download keeps dropping after a while. I keep getting the following message:

*"Unstable network connection. Please check your connection and try again. \[Error code: 207\]"*

The client manages to download a few gigabytes, but then the connection times out. Hitting "Retry" resumes the download from where it left off, but it inevitably fails again with the same error. 

**SideNote:** I didn't encounter a similar error with Neverness to Everness, and it installed without any issues.

The interesting part is that I never encountered this issue when I was on Arch; the client downloaded and updated perfectly fine there. I should also mention that I am running zapret on my system for DPI bypass. I'm not sure if its packet manipulation is interfering with the game's CDN connection specifically on NixOS, or if it's a Wine/Proton isolation issue.

Has anyone else encountered this download issue while installing through DW-Proton, specifically on NixOS? Are there any specific environment variables, winetricks, or NixOS networking quirks I might be missing for Heroic?

**System & Setup Info:**

* OS: NixOS
* Compositor: MangoWM (Wayland)
* Launcher: Heroic Games Launcher
* Proton version: DW-Proton Latest
* CPU: AMD Ryzen 5 5600X
* GPU: NVIDIA GeForce RTX 3060 Ti
* RAM: 16 GB
* Network Tools: zapret

**Heroic Environment Variables in use:**

* PROTON\_USE\_NTSYNC=1
* PROTON\_ENABLE\_WAYLAND=1
* DXVK\_ASYNC=0
* GAMEMODERUN=1
* \_\_GL\_SHADER\_DISK\_CLEANUP=1
* \_\_GL\_SHADER\_DISK\_CACHE\_SIZE=10000000000

Any help or suggestions would be greatly appreciated. Thanks!

[Support] Arknights Endfield Download Failing - Error Code 207 (NixOS)