As the title says, the app will just crash when staking along a line.
My impression it is something to do with the time it takes to reach the target point on the field. It wont happen when finding the point along the line takes a few seconds, it is quite easy the app will crash when you need to walk 50-100 m along the line).
Also, the issue with refresh rates I reported some time ago still persist. After 10-15 minutes staking on the field, the position of the bubble refreshes less frequently. Restarting the app (no changes in the base or rover) will solve it.