This should be an issue for all Barrel crafting processes which take longer than 30 - 60 sec. :
If you start a crafting process like "tanning pelts to leather" and the process is interrupted by Server restart, the Barrel is not accessible any more, that means you cannot open lid!
Items inside the Barrel are shown, but crafting has not completed due to server restart.
You cannot pull the items out and the Barrel cannot be opened any more.
Relog, game restart or next Server restart does not fix this issue!