Have you looked at the Documentation and Help Files? Your question may already be answered.
Crashes are generally caught by Talkback (like Microsoft's Online Crash Reporting).
Please click OK to send those reports to us — it's quick and painless, and helps us to fix the problem quickly.
Not all bugs cause crashes, though. For those that don't, please get in contact with as much detail as possible.
Support is provided using this contact form.
Please provide as much detail of the problem as possible, including the platform you're using.