FlexASIOTest refuses to play 24-bit file

[dechamps]

After creating a 24-bit file using something like:

$ sox --channels 2 --bits 24 --rate 48000 --null 997-1-48000-24.wav synth 30 sine 997 gain -1

With a configuration of sampleType = "Int24", FlexASIOTest 1.4 refuses to play that file:

FATAL ERROR: Cannot playback from file: Unable to read input file: Attempt to read a non-integer number of channels.

This looks like a bug in FlexASIOTest, not FlexASIO itself.