Please help! Error loading CKFinder after upgrading

I just upgraded to the latest version of CKFinder, being careful to keep my existing configuration intact in the new version. Now when ckfinder opens in the browser, I get a javascript error: "Cannot read property 'value' of null". My guess is this has something to do with the folders list because no folders appear in the list.

I'm not really familiar with CKF, so please let me know if I can provide any more information. I'm upgrading to correct a production issue related to an old bug in the thumbnail process.

Regards!

-dan