I upgraded my firmware and app on iPad Mini last week, after update was frustrated by maximum altitude reached @ 98 feet.
I forced the app closed, reopened it and the altitude used the setting in the app.
Tonight I sent drone up to take pictures of sunset, got to 98 feet and max altitude warning again, flew out towards north and maximum distance warning.  I noticed the aircraft was moving left and right approximately 15 feet on it's own, then compass error.
Flew aircraft back, landed and uploaded log to airdata.com for analysis.  There's not much to look at.
This aircraft was sent to DJI earlier this year or late 2016 for compass error and a fly away which I was able to regain control.  They replaced a motor and main logic board.  
I don't fly when it's raining, haven't had any rough landings.  

Here's airdata's analysis of log:

A	00m 00s	0.0 ft	0 ft	Mode	[url=]Mode changed to GPS_Atti[/url]
B	00m 02s	0.0 ft	0 ft	Mode	[url=]Mode changed to AutoTakeoff[/url]
C	00m 02s	0.0 ft	0 ft	Tip	[url=]Tips__Taking Off[/url]
D	00m 04s	3.0 ft	1 ft	Mode	[url=]Mode changed to GPS_Atti[/url]
E	00m 29s	92.8 ft	2 ft	Warning	[url=]Warning:Max Flight Altitude Reached. Adjust in Main Controller Settings if necessary[/url]
	01m 25s	97.4 ft	0 ft		[url=]90% Battery[/url]
	03m 46s	97.8 ft	1 ft		[url=]80% Battery[/url]
	05m 50s	97.4 ft	133 ft		[url=]70% Battery[/url]
	05m 52s	97.4 ft	134 ft		[url=]70% Battery at maximum distance[/url]
F	06m 15s	98.1 ft	126 ft	Mode	[url=]Mode changed to Atti[/url]
G	06m 15s	98.1 ft	126 ft	Warning	[url=]Warning:Compass Error. Exit P-GPS Mode[/url]
H	06m 16s	97.8 ft	119 ft	Mode	[url=]Mode changed to GPS_Atti[/url]

Please try to re-install the APP and login your DJI account. Then do compass calibration as well.

I uninstalled app on iPad Mini 2, reinstalled, tried to calibrated compass, failed said magnetic interference.  Moved everything, re-calibrated compass succeeded but then said compass error exit P-Atti.  Took to third location, re-calibrated compass, succeeded.  Send aircraft up 50 feet (estimate) noticed settings were in metric forgot to change after reinstalling app.  Flew up past 32 meter max altitude error I'd had, no error, flew  200 feet away, no error.  Flew back and landed.  Went to look at the warnings, only thing shown in warnings was taking off, nothing about compass error or re-calibrating.  What is going on???

Central Maine D Posted at 2017-9-1 06:21
I uninstalled app on iPad Mini 2, reinstalled, tried to calibrated compass, failed said magnetic interference.  Moved everything, re-calibrated compass succeeded but then said compass error exit P-Atti.  Took to third location, re-calibrated compass, succeeded.  Send aircraft up 50 feet (estimate) noticed settings were in metric forgot to change after reinstalling app.  Flew up past 32 meter max altitude error I'd had, no error, flew  200 feet away, no error.  Flew back and landed.  Went to look at the warnings, only thing shown in warnings was taking off, nothing about compass error or re-calibrating.  What is going on???

Had you upgraded the firmware as well? The latest firmware of the drone is v1.11.20, please upgrade if necessary.