when people on  my server buy ites they are always broken this is happening since the latest update

I believe you have not actually updated in a long time please follow the update notes from previous updates.

go into your game server make sure you have the permission guishop.admin and do /update in-game to update your config.

i do have "AllowSellOfUsedItems": true,
but the damaged items are still not sellable.
I also ran the /update and gave a confirmation msg
after reload it still doesnt work as expected.
Any idea why?

Fully broken items are not sellable inside of the guishop plugin. 

Used items that have condition values are.

You can add me on discord @ Khan#8615 and I can help get this issue fixed for you.

thanks, youv got my invite from "Hakkai"