I am a iPad 2 user, when I want to watch BD movies on iPad 2, I will use foxeal blu-ray ripper, and it works well, but now, I have a question:

1. I conversion using foxreal's iPad Video h.264 (mp4) for conversion, the
video converted okay and plays on my pc, I have not tried other format.
2. There was no error message during the conversion.
3. The output size was 1.7gb
4. I could not open the Videos app while the BD movie was in it with other
videos converted from regular dvd's, after I removed the BD movie, the
Videos app opened with no problem.

what's wrong with my iPad 2

The easiest first way to try to solve ‘unexplained’ or ‘unusual’ problems with the iPad are:-

Force the offending app to close. If you have iOS 4.2 or 4.3 double-press the ‘Home’ button to bring up the multi-task bar at the bottom of the screen. Press *and hold* any icon until they start to ‘jiggle’. Then tap the top left-hand corner of the app that you want to close. It will ‘disappear’ from the list. Don’t panic - you’ve not deleted it, just closed it. Now tap the Home screen and the multi-task bar will disappear. Re-open the iPad’s app and see if the problem has resolved itself. If not, it’s on to possible solution number two!!
Restart the iPad. Press *and hold* the Power button. After a couple of seconds a slider control will appear asking you to confirm that you really want to switch the iPad off (this is all you’ll be doing). Slide the control to accept. A rotating white ‘bezel’ will appear in the iPad screen as the iPad powers down (it takes a few seconds, just like it would if you were shutting down your PC). When the screen of the iPad has gone completely blank, press *and hold* the Power button for a couple of seconds until the white Apple logo appears and the iPad starts to power up. This takes several seconds, so be patient. During the power up the automatic screen orientation function is disabled, so don’t panic. A few seconds before the power up is complete, the iPad plays a little ‘jingle’ and then you’re back to the Home screen. Restart the iPad’s app and see if the problem persists. Apple (and Forum members) recommend that you power down your iPad at least once a week, just as you might regularly completely switch off your PC. The normal procedure of just briefly pressing the Power button of the iPad merely puts it to ‘sleep’. Most Forum members have found that one of the two methods I’ve mentioned here cure a whole bunch of unexplained problems and are an easy first step to resolving most anything that happens on the iPad.

Tim
Scotland

Which video app are you using? I know AvPlayerHD will play high def. .mp4 files. Maybe the bit rate was too much for the stock player(if that's what you're using) and it caused the app to hang?

Thanks, everyone. I figure out what was wrong, I restored our iPad to the original condition,
reloaded the same BD concert as well as another BD concert now Videos can
open and close with no problem.