Seems to be happening to me every time they release an update. This is on the PC of course.

Close Origin.

Look in the registry by typing regedit in the start search box from the Windows start menu. (wrote this for the BF3 forum)

Go to HKLM\Software\Wow6432Node\EA Games\Battlefield 3 and note down what is in the Install Dir field.

Then double click it and in the Value Data field delete what is there and click OK.

Then run BF3 from the icon again. Origin will load and moan that BF3 doesn’t appear to be installed (I’m assuming it clears some cached data at this point maybe?).

Close Origin again.

Go back to the registry entry above and put back what was in Install Dir field.

Then run BF3 again. Origin now saw it was installed and ran the Battlelog. I could then play again.

May work for you.