A few days ago, OrnLu suffered (again) the loss of all of his (gold) campaign medals.
Like most of us, I guess, I’ve also encountered this problem and lost medals (even whole campaigns). Therefore I now use an easy trick to easily get lost medals back at any time. 
This is what has to be done:
1) Win the scenario
2) +BEFORE YOU LEAVE THE MAP+, save the game.
It’s totally possible to save a game even if one has already won.
That’s literally already it.
If now at any time the medal disappears, you do the following:
→ Load the saved game.
You win at once and the medal is back. 
5 Likes
Will this also works for saves from older patches?
1 Like
Yes, this also works for saves from older patches. 
2 Likes
So your suggestion is just to play again all the campaigns and save it when you win? But this is already what bother people and it is annoying to do and play all campaigns again. Your suggestion will not solve the current problem, it will solve it, if it will happen again in the future. Well in general still better than nothing.
About the same topic @TWest6709 introduced another solution too.
Note my suggestion is for simply unlocking the scenarios, not restoring the medals.
2 Likes
You could alwats save your game data efore a patch and then reupload if you lose progress
