Crashes are almost always caused by shell extensions, and occasionally by bugs in Opus itself.
Where to start depends on which action(s) trigger the crash.
The following guides should help:
[ul][li]Crash, exit or high CPU usage when viewing certain directories[/li]
[li]Crash, exit or high CPU usage when right-clicking certain files[/li]
[li]Crash dumps for bug reports[/li]
[li]General slowdown or instability investigation steps[/li][/ul]