Application crashes after some time

I am not actively working with that application for 12 hours. I have to leave the application running for all the time. When it runs overnight, next morning the application crashes.
Also, I have tested the application time for crash. It crashes only after 12 hours. IT does not crash before that.
What may be the reason ?

Hi,
I have a VB.Net application. I leave the form run for about 12 hours. Till 12 hours the application runs good. After 12 hours the application crashes on whatever action is done on the form.
Can anybody tell the reason for this ?
Might this be a problem with the database connections.
How can I know the reason why the application crashed? Is there a way to get a log entry at the time of crash to record the reason of...