This is the fix for the Battlelog error where it says you do not have the expansion installed (any of the current ones)
In windows 7 go to the start menu
type "Regedit" without quotes
click the program named regedit
it will come up with a window that has a sidebar with folders on the left side of the window.
expand (click the black triangle next to the name) the folder named "HKEY_LOCAL_MACHINE"
expand the folder "SOFTWARE"
expand the folder "Wow6432Node"
expand "EA Games"
expand "Battlefield 4"

now with it expanded it should look something like this:


under your Battlefield 4 folder there should be 5 subfolders (as of 5-11-2014: When they release the last two expansions you will need "Xpack3" and "Xpack4")
DLCs
InstallOptSelect
Xpack0
Xpack1
Xpack2

If you do not have all of them dont worry, that's what we're here to fix.
right click the Battlefield 4 folder

on the dropdown menu put your mouse on "new" and when the second menu drops down click "Key"

it will make a subfolder, and you should name it whichever of the 5 folders you do not have.

So if you already have DLCs, Xpack0, and Xpack1, name it "Xpack2"

once you typed it in, press enter on your keyboard

now click on the folder you just created

move your mouse to the right hand side of regedit and right click anywhere in white area.

hover your mouse over "new"

on the drop down click "string"

it will create a new item in the white area with the cursor ready to edit the name.

Name it "Installed" with a capital "i"

hit enter on your keyboard

double click on the new file you just named

a window will come up with two text boxes

erase everything in the bottom of the two spaces

type "True" with a capital "T"

hit enter on your keyboard.

now, repeat those steps until you have DLCs, Xpack0, Xpack1, and Xpack2 in the subfolders and each of those has a file named "Installed" with a value of "True" in it

close origin (if it was running) and open it again

run battlefield 4 from origin and join a server

Boom
you're done.
Hope i helped!!

Dusty

I had to use this fix the day the second expansions released.  Thanks for posting.

As with any time one does into registry editing ,  back it up first!