No character after entering game, disconnects a few seconds later

After the waterlogged update, first it was not possible to enter the server, now after entering it the character is not displayed. The center of the screen where the character (Wormwood) should be is blank. The game shows the character's pet and the sparkles of its walking cane, but the character does not appear and cannot interact nor move. Up to several seconds later, the server is disconnected. The world is about 2,000 days old, all other worlds are working properly, though It was not possible to connect to them up to hours after updatea at first. The situation lasts since two days.

Edit. 
The server started up, but some of the structures disappeared - all kinds of trees, walls, fridges ...

After rollback the server probably works properly.