Trying to record an NDI Input (PC running Powerpoint) on vMix

When I click on START on MultiCorder (or click the MultiCorder icon on vMix to start the recording) I get the error:

Recording timed out waiting for first frame. MC_OK.Buffer_WFF

The logs report:

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ffmpeg started on 2017-05-16 at 15:56:19
Report written to "I:\\MultiCorder2 - NDI PP-PC (Microsoft PowerPoint) - 16 May 2017 - 03-56-19 PM - 00000.ts.log"
Command line:
"C:\\Program Files (x86)\\vMix\\streaming\\ffmpeg.exe" -report -y -f asf -i "\\\\.\\pipe\\34472dc1-982b-4013-a009-8611646fd24c" -r 15 -pix_fmt yuv420p -vcodec mpeg2video -maxrate:v 8M -minrate:v 8M -b:v 8M -acodec mp2 -b:a 128k -f mpegts "I:\\\\MultiCorder2 - NDI PP-PC (Microsoft PowerPoint) - 16 May 2017 - 03-56-19 PM - 00000.ts"
ffmpeg version 2.8.git Copyright (c) 2000-2015 the FFmpeg developers
built with gcc 4.8.1 (rev2, Built by MinGW-W64 project)
configuration: --enable-gpl --enable-version3 --enable-libx264 --enable-zlib --enable-libfaac --enable-nonfree --cpu=i686 --enable-nvenc
libavutil 55. 2.100 / 55. 2.100
libavcodec 57. 3.100 / 57. 3.100
libavformat 57. 2.100 / 57. 2.100
libavdevice 57. 0.100 / 57. 0.100
libavfilter 6. 9.100 / 6. 9.100
libswscale 4. 0.100 / 4. 0.100
libswresample 2. 0.100 / 2. 0.100
libpostproc 54. 0.100 / 54. 0.100
\\.\pipe\34472dc1-982b-4013-a009-8611646fd24c: Invalid data found when processing input


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First time using MultiCorder (just upgraded to 4k from HD)
Nothing else is recording/streaming at this point, just recently rebooted, drivers appear to be latest versions, Windows 10, vmix 19.0.0.47. Happens whether it's my main broadcast vmix save file, or a brand new blank setup.