Did you once have Battlefield 3 installed from Origin? Did you decide to repurchase it on Steam because reasons? Are you now not able to launch the game? Yeah, me too. After reading countless guides and reading typical troubleshooting dribble, I think I may have discovered the reason.

The explanation is that Battlelog is failing to locate the Steam installation and may instead be searching for your prior Origin installation causing it to hang up on "Initializing" and failing to launch altogether. Here are the steps I took to resolve this.

1.) Uninstall Origin and restart your PC
2.) Delete the following folders (if the folders are already gone then great!)
- C:\Users\[USER NAME]\AppData\Local\Origin
- C:\Users\[USER NAME]\AppData\Roaming\Origin
- C:\ProgramData\EA Logs
- C:\ProgramData\Electronic Arts
- C:\ProgramData\Origin
3.) Run CCleaner's Registry cleaner https://www.ccleaner.com/ and remove entries related to EA, Electronic Arts, Battlefield 3 and Origin. If it's your first time using a registry cleaner, you might need to do some more research.
4.) For Chromium browsers I also went to https://battlelog.battlefield.com/bf3/ and went to "Site Settings" and Cleared Data and Reset Permissions.
5.) Reinstall Origin https://www.origin.com/usa/en-us/store/download and watch Origin revalidate your games. This should occur automatically upon launching the program. Once this completes, you can open the Steam version of Battlefield 3 and watch it launch Battlelog. Choose a server, launch the campaign and play!

***This was a quick 5 minute write up and I'm going to need some feedback. I am really busy and may not be the most responsive so give me some time.

Something to note: the "white screen" issue when pulling up the game is caused by RivaTuner Statistics Server which is included in programs like MSI Afterburner. Just add bf3.exe to the profiles list and set the "Application Detection Level" to "None."