Over the past couple of months we have received feedback (and a few App Store reviews) that Notebooks refuses to start up on some iPads. We have been unable to reproduce this on any of our devices, and most of our iPad users don’t encounter this problem, either, which is why we have not been able to provide a fix yet.

For those struggling with this issue there seems to be a common pattern: launching Notebooks fails in portrait mode, but launching it with the iPad in landscape orientation works fine. So using the iPad in landscape mode could be a workaround until we are able to provide a permanent fix…

Update 2016-03-26: This problem has been addressed and fixed in Notebooks 8.2.3  
 

Startup Issues on iPad (Portrait vs Landscape)