While I'm working on a project, the audio was muted.   I can hear the audio in the Audio Cleaning window, and I hear it in other projects.  I checked every audio control/button I could find, both in the timeline view and the audio mute control in storybook mode.  Everything is okay.

I'm thinking I hit a key combination, but I have no idea what.  I don't see anything relevant in the keyboard shortcut list.  At this point, I'll have to revert to a backup, the most recent with the audio means I have to redo 10 minutes of work. 

I would sure like to know what I did to mute the sound.

Also, a  few  times when I returned to work on a project, the text I entered on frames in Edit mode with the Title tools are invisible.  They can be seen when select them (on the track), and I can make changes to them.  But  when I release   the selection, it's still invisible.  I'm able to make new labels, even with copying and pasting the text. 

I would so much appreciate any ideas to make these fixes.  Thanks.