If the Luscii app crashes and does not work as you are used to, you can hard close the app and reopen it. In many cases this solves the problem and the app works as it should. You can perform the following steps to hard close the app.
Tap the three vertical dashes (the recent key)
An overview of all open apps opens as "small" tabs
By swiping horizontally you will see all the last used apps, look for the Luscii app among them. Do you see the tab with the Luscii app in front of you? Then drag it all the way up to hard close the app.