You cannot edit your VRChat data while the Unity Application is running.

[aLpha]

pls help !

[Zebuun]

You need to delete camera or stop preview

[princess saki]

I am having this problem too and I have no idea how to fix it.

[phantmn]

I thought I had this same error too, but it turns out completing the process for me was on the "Game" tab in between "#Scene" and "Asset Store" in the display area in my Unity project. That is where I finished the uploading process.

Cheers! and good luck.