STRs: - go to mozilla.org - break anywhere - go to Scopes panel, find window > location >href - click on a link The URL gets loaded and replaces the debugger UI. Only way to restore the debugger is to close and reopen the toolbox. See attached GIF 
STRs:
The URL gets loaded and replaces the debugger UI. Only way to restore the debugger is to close and reopen the toolbox.
See attached GIF