Every time I try to run the reverb/echo effect on a sound clip, I keep getting the same error message:
“Internal error at Sequence.cpp, line 1167.”
I only updated to the beta version of Audacity 2.2.0 a week or so ago, and I have not had this problem until just now. 
steve
2
I suspect that the project may be damaged, so first thing - back-up as much as possible now:
- Save the project with a new, unique name (File menu > Save Project As).
- Export each track as WAV files -
- if there is only one track, then “File > Export Audio”.
- If there are several tracks in the project, select each one in turn and “File > Export Selected Audio”
Now try applying any other effect - do you get the same error?
Try applying the effect to a different track - do you get the same error?
It doesn’t work for me either. I am on Windows. When I apply reverb, the waveform’s visual display changes, but there is no sound difference.