Retroarch doesn't start: "avcodec-56.dll is missing" System Error HELP!

I’m so stumped by this that my head hurts. I was able to start retroarch yesterday, configured some settings and everything. Why this is happening today I don’t understand.

I get a system error saying I’m missing avcodec-56.dll… I’m running Windows 7 64-bit with Retroarch v. 1.2.2 and I downloaded RetroArch_1.2.2.7z under the win-x64 section.

Thanks for the feedback!

EDIT: It started working all of a sudden. No idea what changed. I will update if it happens again.