E_AUTH_BAD_DEVICE_KEY_OR_PKCS12 and Kobo ePubs

I have a MacBook Pro running OSX 10.9.3 and Adobe Digital editions 3.0. I have been able to download ePubs from Google Play Books using the acsm files I get from Google with no problems.

Enter Kobo.

I bought my first Kobo eBook, and now I want to download it as an ePub. So, I select that option from the Kobo website, and an acsm file is downloaded to my Mac. I click it, ADE opens, but then I get the E_AUTH_BAD_DEVICE_KEY_OR_PKCS12 error. I can't download the ePub at all.

Any ideas as to why this isn't working with Kobo, though it works with Google Play books? 

Thanks!