Using a WMD driver, with project audio set to 96kHz, importing a 24 bit 96KHz file no wave form appears, and it plays at 1/2 speed. Change the project to 48Khz sample rate and it plays just fine, still no wave form.
Close HitFilm and change default audio driver in Windows to ASIO, external audio device, restart HF3, same problems.
Start new project, set audio rate to 44.1, import a 16bit 44.1KHz stereo uncompressed PCM/WAV file. Wave form appears but HF3 will not allow it to be placed on the time line. Removing that file from the media list and try importing a 16bit 44.1Khz -128 MP3 causes an unexpected error.