This is what is happening, I have been using the Backpack mod for many months. No problems, mostly it works fine, now I have one player that can not open the /backpack mod for his items. All other players seem to be working fine. Have made sure I have the update, removed the mod and reinstalled the mod. Verify perms on the server, even given the player all the permissions. Still not working, have restarted the server, player has re-installed the rust game, I beleive he is using a mac laptop, not sure if that matters. The backpack mod was working fine for him in the past.

did he try using F1 to open console and then type bind b backpack.open
and then press the b key to see if it opens ?

i am using the backpack mod by white thunder. usually players in the chat window type /backpack and it opens for them. We will give this a try. my player tried this, did not work.

Then the player is doing something wrong as it always works (i have been using the plugin since it came out)

Merged post

Did you check that the player concerned has the permission  backpacks.use  granted to them ?