the first thing you should do is download and install the latest stable release. the link for the latest build can always be found in the thread pinned to the top of the MC12 forums. (or
click here)
Sometimes, the update alone is enough to fix things, but if it is still crashing for you, you should post again giving as much detail as possible as to what MC is doing when it crashes. You should also include your 'system info'. To get that, while MC is running, click on "Help > System Info" and the detail will be placed on your windows clipboard, simply paste that into your post.
Enabling logging may be useful. Help > Logging > enable the "Output to a logfile" option and restart MC.
If you're using the auto-import feature, it may be worth turning that off and see if that stops the crashing. To turn it off, Click on "Tools > Auto-import options" expand "options" in the right pane and deselect "run auto import in the background". Press OK.
-marko.
