Igor In answer to your request I list below my workflow. 1)Working with one session only of PTE. 2)Progress bar seen each time waveform works. If progress bar does not appear neither does waveform. 3)Step by step. Open PTE, timeline visible, press waveform button and sometimes it works and sometimes it fails, close and reopen PTE until it works. 4)I am afraid I am unable to make a screen video. Many thanks for taking the time and trouble to try and rectify this problem. Regards Gwynn