I think this is due to basic misunderstanding of encoding formats, containers or a setting that mistakenly got changed on my end. Please help a dummy out as I've struggled with this for days.

I'm using a USB dongle to stream SD. I asked a couple of advertisers to send me commercials for me to insert. They came in a few different formats. When I load a big .mov file, it will play and stream fine. But the others are mp4s and when I try to play them I was getting an error in VMIX v13 when I would push the "Stream" button along the lines of "Audio capture device is not compatible with settings. FMLE Exited".

I uninstalled FMLE. Re-installed it (several times). Upgraded to VMIX v14 beta etc. I also did my last broadcast using FMLE - so it is working fine. Now my error in VMix v14 is simply "Streaing has stoppd unexpectedly FMLE Exited". Again, a .mov will stream, most other formats wont.

I downloaded Handbrake and tried to convert these files to other audio or video formats (tried a bunch of different settings) and I get the same errors.

So I guess my most basic question is... what is the preferred program similar to Handbrake to convert files of different types... and what are the preferred output settings to get a file that will for sure stream in VMix without any issues.

If you need any additional info to help, please don't hesitate to ask. Thanks

I also think part of the problem is that I messed with some audio settings somewhere. Here are my settings.
Master Sample Rate: 4410
Master Bit Rate: 16 bit PCM
Recording Audio: VMix Audio
Format: 44100 Hz, 16 bit 2 channels