We are having similar issues.
Our two Server crash around 2-6 Times a Day, this only started happening after the x64 Update an never happend before, mostly during prime time with high loads on the Server (~70-80 Players).
Next Time it crashes i will include some RPT files.
Also coming from the Life Community i know that many other Server are experiencing the same Problem and are desperately waiting on a Fix from Bohemia, as there is broad consent that this must be on bohemias side (i myself haven't analysed the logs so i can only repeat what i hear/read).
EDIT:
To have an Idea of the frequency: Our server ran the whole day and than, when the load rose, started crashing : 17:50, 18:16, 20:11, 20:36
Here are the RPT Logs just before the crashes occurred https://drive.google.com/uc?id=0B_TmB6GeWD7PUlh0ZS1jbzBpaWM
The Logs are pretty small, as Server generally run better with the -noLogs Parameter, i might turn the Logs on this afternoon to generate a few complete sets if needed.
As i am not sure if the mdmp, bidmp files contain sensitive Information, i will not post them publicly, but if any BI DEV is interested in taking a look please send me a Message.