triggers are not working in character animator

What can help is screen shots showing the puppet hierarchy and how you have defined the triggers. Also do you have the "blink together" flag on in the Face behavior? Showing the definition of the triggers panel would also be helpful as it will show the definitions of swap sets etc as well.

Then share the keys you are pressing so can compare to the definitions etc. 

In general triggers for me has been probably the most stable feature - so it is more likely to be a rigging issue. There are a few edge cases like triggering multiple triggers at the same time, and blink is interesting since it is also a face behavior controlled thing.

Regarding expressions, which expressions where you trying? If you did not change anything, i would check the lighting on your face. If you look at the camera window in the top right, do you see little red dots on the face? They are the tracking marks. Only two face expressions control the mouth - smile and surprised. You might use a neutral expression and click the reset post button there as well - maybe the initial picture it used you were already smiling (meaning you would have to smile super hard to trigger a smile expression). The rest of the mouth expressions are controlled by sound analysis (LipSync behavior). So it would be useful to know which expressions or sounds you were doing.

Happy to help try and track down the problem, but a bit more detail would help with that if you can.