Not getting achievements In Civilization 5 is there a difference between silver and bronze achievements?

I just finished a game as Attila. I won a militaristic victory on level Prince(4), small map, standard game. I did not get my steam achievement for this victory, Scourge of Everyone.

Then I noticed that some achievements have silver locks and some bronze. Could it be that I cannot unlock the bronze until I complete the silver ones? What other reason is there for not getting the achievement?

FYI, I just beat the game again by replaying from an auto-save and this time I saved it on the very last turn. Still no luck.

UPDATE: I think Rob and Robin Hood are correct because I did get the Enlighten Ruler achievement (unlock all social policies) but I am not getting the leader ones This time with Montezuma

UPDATE: I have the Brave New World DLC. I just finished a new game with Montezuma and received the Montezuma's Revenge achievement.

Solution 1:

The reason why you may not be receiving the achievements, aside from perhaps not unlocking them fully, is that they are not awarded whenever you have a mod enabled and most (if not all) achievements will not unlock if you are playing a multiplayer game. Both of these will not only prevent you from gaining an achievement but also halt any progress you may have gained on one (ie forests chopped during the time you are playing with a mod does not count towards the number required for the Paul Bunyan achievement). There's also a chance that if you disable reward pop-ups in one of the Options menu (off by default I believe), you will not receive achievements either. If you have previously received achievements, I'm assuming it's either a mod or you were playing with someone else that is the main cause of your problem.

As for the color, they refer to either the vanilla game or Gods and Kings expansion pack. They do not have any impact on the order of how you receive them and one does not necessarily unlock a different one for you (although you can gain multiple achievements by doing one action, like finishing a game with a particular leader).

If you need help with getting a specific achievement, this Civ Fanatics forum post has a great list. This is one of many.

Solution 2:

The bronze lock simply denotes that those Achievements have been added with the Expansion "Gods and Kings". The achievements for the next expansion have all gold locks. All Achievements should unlock the moment you earn them.

I have about 65% of all Achievements and never encountered one that is not unlockable before you have unlocked a different one.

I have unlocked "Scourge of Everyone" successfully btw.