I thought it was too ridiculous to post this, but then I saw a Mac user with the same problem. 1
The problem is as following: I bought the HIB4 and got a multiplayer key which contains the V character (86 in ASCII). When I type the code and press V key, nothing happens. It’s really weird…
Since I’m on Linux, is there a file in ~/.positech/GSB where I can manually add the key?
“You rang?”, says the genie in the bottle. 
Your solution - which afflicted both Linux and Mac users, yes - is found here. Enjoy!
I actually think it affected windows users too. It had to do with a bad switch case logic, where the “Ctrl-V” (paste) shortcut was checked and if the CTRL key wasn’t down, would just eat the V instead of passing it along. The (soon to come) updated linux binaries fix this issue.
This was never an issue before, because the multiplayer keys never had a V in them until the HiB #4 