Nothing has changed, yet I can download other full games perfectly fine.
I've reinstalled Steam, done the "steam://flushconfig" trick, disabled any programs that would have interferred with Steam, reset my router, and some other possible solutions but nothing has worked.
What bothers me the most about this is other games like Elder Scrolls: Skyrim, Amnesia: The Dark Descent, and PAYDAY: The Heist were deleted but redownloaded with no issues.
It is possible that the steam web browser’s cache has been corrupted.
If the web browser cache is corrupted the store might not load properly.
There may be several reasons behind this such as your internet connection might be slow or there may be a problem with your HTML cache.
One effective way is to delete Steam and re-install it again.
What has happened, is that I start downloading or updating one of those 3 games.
However, the download speed that it reaches suddenly decreases and eventually stops, leaving an "Update Required" message on the Downloads page.
Later on, you will be seeing a window consisting of all the names of the Users who use this computer. Finally, you will be seeing a folder named “htmlcache”. In the dialogue box write “C:\Program Files (x86)\Steam”.
Click on your user name and advance to find a folder named “App Data”. Once you are in the cache folder, select all the items and delete them. Or if you installed Steam in another directory, you can browse to that directory and you will be good to go.
If you followed all the steps correctly you should now have two steam applications that can be used to access Steam.