It's up to Microsoft to fix the issue. marko already posted the files you needed in the other topic to get conversion working again - just look for the link located in the word here.
Would you please be so kind as to actually post the download URL for those files ?
There is no link in your post. I searched the other topic linked by marko above, and didn't see a download URL in his post either.
Never mind, I found it! I need to get more sleep.
I'm sure there has been some sort of change by Microsoft that affects JRiver Media Center. However, I have other non-MS programs that are still able to output Windows Media - Cyberlink PowerDirector 14 is one. I'm running an encode right now without any issue. It's an audio/video encode, though, not audio-only, and the program only offers a set of fixed profiles, not including lossless - I don't think they offer lossless for video. Is Windows Media only broken for Audio in JRiver Media center ?