This:

"CannotShare": "You cannot share blueprints with this player because they aren't a friend or in the same clan or team!",

does not show when i try to share my blueprints with people that are not (in) my team/clan/friends. Only response it gives is nothing.

Which of those options are you using on your server?

Sorry for the delayed response:

I gave people the option to do /bs share [player]. But there is supposed to be a response message that you can't give players your blueprints because they are not in your team/clan/friends.

Sorry my question was a bit unclear I wanted to know which group systems you are using such as friends, teams and clans.

Oh im using:

uMod - Friends by Wulf

and

uMod - Rust:IO Clans by dcode

I believe Rust:IO is causing the issue for you as it is not supported. I will add support for it within a patch that I will releasing within the next few days.

Thanks for your help!