Phonology assistant: play audio - is it working?

I knew that Phonology Assistant (4.1) can play audio, but I haven’t recently been able to make it work. I have recordings in an audio writing system in the lexeme field. Some files were recorded within Fieldworks (9.1.16) and some outside and attached separately. The audio file names are visible to Phonology Assistant but it doesn’t play. Any advice from anyone?