Hard to say what is causing this, but it is usually [not always] a system fault....this can most commonly be related to system memory [RAM] over burdon.
Not much you can do about it [other than upgrade] except for allowing for this in your work flow, by simplifying the data set you are working on at any given time.
Design Manager Streetscape Limited
Solid Edge ST9 [MP3] Classic [x2 seats]
If you have been clicking 'Yes' on the crash dialog to send the logs to SE, you can ask for an investigation of your crashes by contacting your VAR or GTAC (depending on where you are and if you have maintenance). The SE development team can then investigate, based on the log files, if your issue can be resolved in code.