Sometimes software failures can cause the touch interface to crash or freeze. The best way to resolve this kind of issue, if it recurs, is to clear the cache and local data of the touch interface. This will restore the touch interface to a default state without damaging the software.
To begin, it can be advisable to backup your printer specific settings, located under Settings->Printer->Print Area. It is recommended to write these settings down or take a picture of them.
Then swipe down twice from the top right of the screen, and select settings.
Then choose the apps menu and select MatterControl.
Then press "Clear Cache" and then "Clear Data". This will revert MatterConrol to its original state.