suddenly no longer works in windows 8.1

suddenly no longer works in windows 8.1 "start menu has stopped working"

Problem Event Name: APPCRASH
   Application Name: StartMenuX.exe
   Application Version: 5.1.2.0
   Application Timestamp: 5327150th
   Name the module with errors: StartMenuX.exe
   Module with errors version: 5.1.2.0
   Timestamp module with errors: 5327150a
   Exception Code: c0000005
   Offset exception: 000000000000c4f9
   OS Version: 6.3.9600.2.0.0.768.101
   Locale ID: 1040
   Additional Information 1: fbb1
   Additional Information 2: fbb165165faafaa7031413a3208d8098
   Additional Information 3: 4f9d
   Additional Information 4: 4f9d3c62c24d73234dfd0df490145ac4