Not so unusual. I also have the same problem.
I have also tried installing both 32 & 64 bit versions directly from the website but get the same error.
I am sure it is a Windows 8.1 issue as it worked fine under Windows 8.0.
Windows 8.1 is to be dropped but not until 2015.
This is a great application that I use in many ways.
I hope the problem signature below helps in some way.
Problem signature:
Problem Event Name: APPCRASH
Application Name: Bulk Rename Utility.exe
Application Version: 2.7.1.2
Application Timestamp: 4c1db12a
Fault Module Name: SHELL32.dll
Fault Module Version: 6.3.9600.16474
Fault Module Timestamp: 52902a5b
Exception Code: c00000fd
Exception Offset: 00007875
OS Version: 6.3.9600.2.0.0.768.100
Locale ID: 3081
Additional Information 1: 7f39
Additional Information 2: 7f392d44555c054679f9cfe0c25acabd
Additional Information 3: a34b
Additional Information 4: a34b830284d650d342443fea67dbf3c1
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