So it's crashing whilst performing the initial scan of your library for problems, and didn't experience this problem before purchasing? Very odd. There are two files that may be very helpful to tracking this problem down, please send them to email@example.com
1) Song Sergeant's most recent crash log. You can find them within (home directory) / Library / Logs / CrashReporter.
2) Song Sergeant's own log file(s). The most recent Song Sergeant .zip or .txt file found in (home directory) / Library / Logs.