March 2015
Hello Stealwars,
Unlocking Battlefield 4 Multiplayer weapons requested from the Battlefield 4 Campaign requires a stable Internet connection. If that has not solved your problem, log out of Battlelog, close and re-open your web browser and re-login to Battlelog or fix Battlefield 4 via Origin by right clicking on the game in your library and scroll on "fix". Please replay the mission of the campaign after trying these procedures.
I hope I have solved your problem,
lMILOUDl
March 2015