I’ve seen others with this issue, but have yet to find a solution. I can upload my avatar as a test build, but when I try to publish it, I get the “Unity is running” on the SDK window, and a grayed out main window. While writing this (and to help others who may have run across this) I found the fix by random chance. VRChat SDK uses the “Game” panel to upload an Avatar. At the top of the Game panel, there is a “Scale” slider. Mine, for some unknown reason, became maxed. Move the slider to the far left. I was just moving windows around and accidently snapped Unity to the side and saw some oversized text. I hope this helps anyone else who is having this issue.