This bug effects Sword Art Online : Redux, and is the reason why the world hasn't been public for the past nearly 3 months, and is now understood what causes it, as written below.
All users in the entire instance of a world is crashed instantly to desktop, the crash is so bad that the log file isn't even written to, or sometimes is only half written. This occurs when someone not Owner/Master picks up any pickup object IF the world contains more than approximately 10500 +/- 500 enabled GameObjects. These gameobjects can be just empty, it does not matter.
To test this a new project was created, added few cube pickups with ObjectSync attached, then created empty gameobject and filled it with 10000 child gameobjects. In this scenario world still worked fine. Then I duplicated this parent gameobject and got total count of 20000 gameobjects on scene. After doing this I noticed:
1. Long black screen when joining the world
2. Picture stutters when I hovering hand over simple pickups
3. Everyones game crashed when non master tries to pickup an object
Then I started disabling gameobjects by large groups and noticed when about 10250 objects left mine client stopped crashing but my friend was still crashing and when only 10050 enabled objects remained both us stopped crashing.
Another thing we reproduced is in world with 10050 objects both of us did not crash but as soon as I opened avatar menu and my friend picked up a pickup I crashed (but he did not), so my enabled gameobject count was increased when I was browsing avatars.
It can be issue with Unity GameObject.Find or something like this. Looks like VRChat checks for all gameobjects in scene hierarchy when doing certain things.
Test world ID with dummy 11000 objects that crashing both of us: wrld_d7ad91c0-1488-485e-afee-82f3c25844d4
Again, it is important to note this crash requires at least 2 people to test, the non-master needs to pick up a pickup object to trigger the crash.