I can fairly reliably recreate this by playing some matches (grouped with a friend) and then exiting the client. I get an R6025 runtime error, and when I close that out I get the standard Windows 7 "MechWarrior Online has stopped working" dialog (both are shown below).


The full problem details given in the "MechWarrior Online has stopped working" dialog are as follows (I am assuming that the hashes given in the "Additional Information" parameters are not privileged information in disguise):
Problem signature:
Problem Event Name: APPCRASH
Application Name: MWOClient.exe
Application Version: 3.4.1.4418
Application Timestamp: 50cfac5e
Fault Module Name: MSVCR100.dll
Fault Module Version: 10.0.40219.325
Fault Module Timestamp: 4df2be1e
Exception Code: 40000015
Exception Offset: 0008d6fd
OS Version: 6.1.7601.2.1.0.256.48
Locale ID: 1033
Additional Information 1: 3252
Additional Information 2: 32528dd6159ece4b0813cd35b5d99269
Additional Information 3: 26c4
Additional Information 4: 26c46992914718aa4e84ae3552ec22b9
Read our privacy statement online:
http://go.microsoft....88&clcid=0x0409
If the online privacy statement is not available, please read our privacy statement offline:
C:\Windows\system32\en-US\erofflps.txt