iPad apps suddenly non functional I play Criminal Case on my iPad and was asked to join  a criminal case group. I clicked "yes" on the invitation and now I cannot access anything on my iPad. 

If I click on any App,  it will open up and then immediately shut down. 

Any suggestions as to how to fix?
I'd take a closer look at the link you used to join the group just to see if it looks normal.

In the meantime I'd restart the iPad and then see if the apps work. If not you may have to backup and restore your iPad. I'm sure that (if necessary) should help clean up that issue. If not, you'll have to go back to factory settings.