i just tried again being logged in to the App Store application on my computer. tried purchasing and crashed again

here are the first few lines of the crashing report:

Process: iReal Pro [1389]
Path: /Applications/iReal Pro.app/Contents/MacOS/iReal Pro
Identifier: com.massimobiolcati.irealbookmac
Version: 6.1 (8202)
Code Type: X86-64 (Native)
Parent Process: launchd [148]

Date/Time: 2015-05-03 09:34:07.880 -0300
OS Version: Mac OS X 10.7.5 (11G63b)
Report Version: 9

Interval Since Last Report: 59206 sec
Crashes Since Last Report: 17
Per-App Interval Since Last Report: 152124 sec
Per-App Crashes Since Last Report: 13
Anonymous UUID: D50998C9-B31D-4733-B13F-ED448D29ADD3

Crashed Thread: 0 Dispatch queue: com.apple.main-thread

Exception Type: EXC_BAD_INSTRUCTION (SIGILL)
Exception Codes: 0x0000000000000001, 0x0000000000000000

Application Specific Information:
objc[1389]: garbage collection is OFF
objc[1389]: cannot form weak reference to instance (0x7fae33239df0) of class StoreWindowController
Performing @selector(purchaseExtraJazzStyles from sender NSButton 0x7fae330e6c30