Sometimes when I'm at the middle of the game it suddenly freezes and when I press window then I can see the error message appears and telling me this:
Unhandled Exception: c0000005
At address: 0043d2fb
Do you know how I can avoid this from happening?
You can't avoid it, it's common that it crashes, the crashes are far less in R2 (supposedly) but do still happen.
Hopefully we can fix all the common crashes in the next release.
When it happens you can close the process from task manager. ;)