This seems to be the same problem every year.
First there is the advertisement that the latest version (in this case version 16) just before the programme gets buggy. It pops up every time I boot the programme, even after asking it nicely not to show up again.
Then the video preview window didn't show up, so I had to press Alt+4. Then Alt+4 (and Alt+3) stopped working. Then the programme crashes with the frame rate problem (something I have had trouble with in the pass with an old computer). And now I can not access the video previewer with buttons OR through the window.
I was looking for an update higher than build157 and couldn't find one. Hench this slightly angry forum post.
I really want this bug fixed so I can get back to work quickly. Many thanks in advance