Follow the instructions below and it should fix it for you:
Solution from eanils http://answers.ea.com/t5/Battlefield-4/BF4-PC-China-Rising-DLC-Problem/m-p/2017595#U2017595
Please first make a backup copy of your registry as described here: http://windows.microsoft.com/en-us/windows/back-up-registry#1TC=windows-7
Next check out these steps below:
1. Log out and fully exit Origin
2. Open your Registry Editor - Type in regedit on the Start Menu Search field and press Enter
3. Navigate through HKEY_LOCAL_MACHINE > SOFTWARE > Wow6432Node > EA Games > Battlefield 4
4. Check if there is a folder named Xpack1 under Battlefield 4
If YES -> Click on Xpack1, on the right pane check if there is a string named Installed, the Value data should be True
If NO - right-click on Battlefield 4 > New > Key
- a new folder will be created, name it Xpack1
- right-click on Xpack1 > New > String Value > name it Installed
- on the right-pane, double-click on Installed, set Value Data to True
5. Exit Registry Editor
6. Log in to Origin and Join China Rising Maps
