Sometimes you start the tournament and then find out that brackets are the wrong size or have the wrong number of placing positions.  If you are using letters and digits for match numbers, "View"/"Emergency bracket repair..." can be used to fix each bracket.  If you are using just digits for match numbers, you'll need the tournament just before "Start the Tournament" was clicked.

TournamentSR automatically saves a copy of this data.  The last part of the file name is ".AtStart" (normal TournamentSR files end in ".xml").  In order to see this file, use the "File"/"Open..." menu and then change the "Files of type:" drop down list to read "All files".  After loading the ".AtStart" file, immediately save it using a different name.  You can then make the bracket changes, restart the tournament, and enter any results that took place before you realized the brackets are wrong.