Crashes upon attempting to open file

I'm sorta new at using MS, but as I was transposing a piece today and as I was two lines from the end, MuseScore crashes. It does this occasionally, so I reopen it and expect to continue on but now it crashes every time I try to open this particular file. I use MS 1.2 and windows 7. I can create and view other files with no problem but it won't let me open this one.
The info from the crash is as follows:
Problem signature:
Problem Event Name: APPCRASH
Application Name: mscore.exe
Application Version: 0.0.0.0
Application Timestamp: 4f5f4d90
Fault Module Name: mscore.exe
Fault Module Version: 0.0.0.0
Fault Module Timestamp: 4f5f4d90
Exception Code: c0000005
Exception Offset: 00040110
OS Version: 6.1.7601.2.1.0.256.1
Locale ID: 1033
Additional Information 1: 0a9e
Additional Information 2: 0a9e372d3b4ad19135b953a78882e789
Additional Information 3: 0a9e
Additional Information 4: 0a9e372d3b4ad19135b953a78882e789

Any ideas? Thanks!