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Heartbeat successful just means the key is correct, not showing up on the server list means you are missing one of the 5 port forwarding things.
thats an issue that a few folks have been getting lately. usually fixed by waiting, resetting router, switching from wifi to ethernet, ethernet to wifi, trying a hot spot, new DNS, using VPN, turning off VPN, using something like Cloudflare WARP, etc.
basically something about your network changing to correct the connection issue to the server. that seems to do the trick.
assuming you are talking about the DLC maps, you need to have the DLC to play the DLC.
"unlock" in the plutonium feature list just means you don't have to do any progression unlocks in order to get to them, but you still have to have the game files to play those files.
DLC game files can be found on Steam.
no... they are very different versions.
@bigmeatythumbs
no this issue does not come with plutonium... works fine for the other 99% of us.
You gotta give us more info if you want better help and wait a little more than 2 hours if you are looking for a good answer. if you are looking for more immediate help, try the discord channel and have a little more patience.
if you install the dual wield cz fix (here in the forum) it will fix that for you...
Sorry man, we can't provide help for pirated files. they are no longer supported.
Get you some steam files!
it seems to be a common connection issue that is usually solved by switching something about your network... VPN, no VPN, wifi to ethernet, ethernet to wifi, using Cloudflare WARP, resetting the router, waiting a day, etc.
Those things are usually what solves it for others. But it appears to be a connection issue between the user and the servers.
launch the game once thru steam and it should get all your dependencies set up (directX being one of them)
unpin plutonium from the taskbar and run it from the actual .exe
when you pin plutonium while it is running, it pins the wrong part and skips the update part. This error is usually a sign of that.
what do you need help with? you have to have the DLCs to play the DLCs... so get the DLCs 
Edit: realizing you might not know where to get the DLCs and that is what you are trying to say... see link below.
https://store.steampowered.com/search/?term=black+ops+2
DLCs are found in: Apocalypse, Uprising, Vengeance, and Revolution.
ok is this a PSA or do you have a question?
yes but it's not in plutonium it's in the game.
in black ops 2 go to OPTIONS -> CONTROLS -> COMBAT -> and set TOGGLE ADS to your desired button.
when in doubt, checking / verifying game files solves most issues!
@FomroMadia , verify game files = check games files... not sure what you were getting at 
nice!
it still crashes after you install the fix?
my apologies, i should have worded that better and i have edited my reply to be more accurate
There are fixes available to install if you search the forum...
unpin your launcher from the taskbar and open the actual plutonium.exe
This problem is usually because you are launching plutonium from a pinned source which bypasses the updater.
sprixxyfr
probably best if you start a new thread and give the full error since this thread is not about your error (and is 2 years old)