If you didn't like farming *bronze* to get the first gear set upgraded, well boy oh boy do I have some extremely bad news for you regarding the rest of the entire game lol

Why it´s possible that the equip of my corpse disapear? Mostly the most worthly equip. This is very annoying for a solo like me.

You can skip the bronze gear next time around and go after trolls instead. Then the bronze grind isn't quite as bad, just be careful in the swamp. I don't bother with making bronze armor anymore.

Where did you lose them? On your character or in a chest? Those are two different saves, character save vs world save, to look for.

it's also possible to enable -console in startup parameters (that can easily be done in one of steam's window in the game properties) and then use devcommands to spawn in replacement gear.

You don't even need to know the exact name of the item, if you type any part of the name it shows you all items that include that word, and once you know the format, you can start typing it out and the choices keep shrinking as you go. if you misstype they all disappear, so back up and keep typing.

if it was stored in a chest. it's gone :(

Save file was corrupted and all your items get deleted.