@Dan Kulp,
I am leaning towards a timeout type issues, but only from FPP Connect and only for .FSEQ files. (Maybe media, but so far that has loaded correctly) The progress bar for the upload pops up but then immediately closes or stalls momentarily without progressing and then closes. It might be nice that if during the FPP Connect upload process that if there were files that did not upload successfully a message box would let the user know. I know the FPP Connect is communicating with the FPP because if I upload UDP data, the FPP instance will have the Reboot flag set.
When you use the MultiSync upload from FPP, it doesn't appear to use the Sparse file format, does it?
Is there a way to create the sparse file in order to do a manual upload?