LG may have exited the smartphone market, but that doesn’t mean that current LG handset owners have switched to other brands right away. LG still offers a generous update policy to those who own a smartphone from the manufacturer, so things could have been much worse. However, unfortunate T-Mobile subscribers who own an LG handset are currently left with nonfunctional phones, with an “LG IMS has stopped” error message popping up over and over again, leaving them unable to do anything on their devices.
Link: Many LG phones are unusable on T-Mobile due to ‘LG IMS’ issues, here’s a potential fix
via http://www.androidpolice.com