Crashing while marking

Can anyone tell me why the latest version of Gospel Library (4.3.1.2), on an Android tablet (2013 Google Nexus 7) with Android OS 6.0.1, does not work without the app crashing when marking scriptures. I don't want to buy a new device just to use Gospel library, so if anyone can help, that would be great!

Is it specifically when you drag the highlight handles to select multiple words that it crashes, or something else around marking scriptures?