Same here. I updated my servers to 306.48 running The Island and Valguero and Valguero crashed like above when someone tried to connect. I was then told that someone who tried to connect to the Island found out their character is gone. I decided to shut down all my servers until more information is released and give the devs some time to fix this mess. My server consoles were also streaming "AllActors" type of errors over and over. Things are not in a good place right now.
Me too. I see that there are many unofficial servers running on the 306.48 and 306.5 server version so it must be something specific to our builds. Are you running any API mods like /Home or /TPR for teleporting? I'm going to try to remove that and see if that makes a difference. I run, Structures Plus, Amazing Spyglass, Classic Fliers, Large Storage Box, Advanced Rafts, platforms plus, castles keeps and forts, and prehistoric structures as mods.