How to fix Assassins Creed 4 Black Flag unable to start correctly 0xc00007b error

"The application was unable to start correctly (0xc000007b)". If this is the error you get when trying to run black flag, this post is for you. The root of this problem is the corruption of one or more .dll files black flag requires to run. .dll files which belongs to directx is most likely the corrupted one. They can be found at "C:/Windows/system32/" if your are using 32bit windows and in "c:/Windows/SysWOW64/" if you are using a 64-bit windows. All of the files which start with d3d belong to directx. Note: if you are using 64-bit windows, there will be directx files in both system32 and syswow64.

To fix this issue, you need to replace these files with fresh ones. Re-installing directx will not resolve this issue because when  the setup detects the file, it automatically skips ahead instead of overwriting. In my specific case, the problem was to a file named "D3DX9_43.dll" You will have to try removing all the directx files from  the folders mentioned above and then re-install directx (Or else you will have to re-install windows). All the files that start with "d3d" belong to directx. They can be safely removed. However not all directx files start with d3d. That is the tricky part.

I recommend that you first remove all the files with "d3d" in the file-name and  re-install directx, and then try to run black flag. If it doesn't work, try removing these 24 files and then re-install directx.
First try the xinput1_3.dll.

1. xinput1_1.dll

2. xinput1_2.dll

3. xinput1_3.dll

4. xinput1_4.dll

5. xinput9_1_0.dll

6. XAudio2_0.dll

7. XAudio2_1.dll

8. XAudio2_2.dll

10. XAudio2_3.dll

11. XAudio2_4.dll