I just want to confirm that I began experiencing the same problem within the past 12 hours or so, using both fre:ac and TAudioConverter 64-bit. I uninstalled, reinstalled, and manually reconfigured the relevant settings, without any change.
Yours is the only post I could locate of anyone else experiencing the same problem. I am running Windows 10.
I would also appreciate any information regarding this situation, as well as suggestions as to viable alternatives. I am in the process of adding some of my music to Google Music Libaray and am unwilling to type in manually all the needed track and album information, as well.