Carrying items from the old version to new version

Hello everyone, first of all I thank everyone's attention.

I have the following problem.

I want to change the version of my old server 97d to version 1.0 or Season2.

But I have problems when I try to import the players with their inventory full of old items, they just get error when I try to do this task, all items have bug, the inventory is full of kriss and bronze armor + 0.

Unfortunately I can't leave these items in the 97d, I really need to keep them, are years of items which players have won in the game.

I hope something can guide me on this problem.

Thank you very much!

I'm sorry for my bad English, I am using a translator.