On this page of the Valheim guide, you will find information about the most common bugs found in the game and their potential solutions.
A fairly common bug. It causes the tombstone to not appear in the game world when the character dies. As a result, you will not be able to recover your equipment. This process cannot be reversed.
Desynchronization in multiplayer
When you are playing with friends, you may encounter a problem with desynchronization. In this case, other players won't see your actions. In extreme cases, others won't be able to use your items or these objects will simply disappear from the game.
If this happens, everyone should log out and log back in.
Corrupted world save
A critical bug that causes the world save to be corrupted – you will lose all progress. So far it is not entirely sure what causes this glitch, but there is a chance that it is related to exiting the game using the Alt + F4 key combination.
Lost gear upgrades
A bug that occurs during multiplayer games. If you hang a piece of equipment you didn't create and then take it off, chances are all of its upgrades will be reset. Therefore, it is better to use crates to transfer equipment.