I am getting compass stuck errors lately too. Restart does usually fix the problem.
I would agree with Tyson that a calibration and IMU calibration should be your next steps, Niall.
A week or so ago I rolled back to 2.9.1 (3.0.1 was not working very nicely on my Samsung Mega). However, I randomly got the Compass Stuck error this morning. Two restarts resolved it, for now.
The video series on youtube here is great for a beginner like me:
This might be a useful resource for those who are looking for free training but are a bit intimidated to jump right into the thorough, but meaty guides like Nilsson and Rupprechts'. (Haven't seen this video series referenced in...