jford,
Thanks for your tip about using LAME ACM version. It partially worked. smile

BIAB 64-bit was immediately able to save to MP3 right after being installed after I downloaded it. Nothing else needed.
And I've had Reaper 64-bit previously able to render MP3's. A year or so ago, Reaper started bundling in LAME during the Reaper install. Works solid.

But the 2 32-bit programs were not able to save MP3 --- RB 2019 and BIAB 32-bit. So, I tried your suggestion here to install LAME ACM. Then, BIAB 32-bit was able to save them, exactly the way BIAB 64 worked. Great, it seems to me the 32-bit version is a little bit faster, but things are working.

However, it's RealBand 2019 that still isn't working ---- I installed with the CMD line as Administrator, run the programs as Administrator, and the menu lets me choose "Save as MP3" ---- it loads the LAME interface, allows me to choose Attributes, and tries to render out, but gives the error message Cannot get Stream Size It does save WAV files just fine. Any ideas?

Jerry
2019 BiaB Megapack (634), RB 2019 (Build 4)
Reaper 5.983 x64, Audient id14 USB interface, Voicemeeter Potato 3.0.0.8, Nektar LX49+, Roland E20
i7-6700K Skylake desktop, 64bit Win10 Pro(1903), 32GB ram, 512GB system SSD + 2TB data SSD