Error "Object reference not set to an instance of an object"

[Jim999AGC]

Hi,

i have the program compiled with the VS 17 under Win7 and tried to run it on the PI with root.
root@pimusic: [...] /RaspiMusicBox-master/RaspiMusic/bin/Release# mono RaspiMusic.exe

I got the following error:

Starting...

Unhandled Exception:

System.NullReferenceException: Object reference not set to an instance of an object.
  at Raspberry.IO.GeneralPurpose.GpioConnection.Allocate (Raspberry.IO.GeneralPurpose.PinConfiguration configuration) [0x00073] in <c4694beda89543a583765d12b492fa36>:0 
  at Raspberry.IO.GeneralPurpose.GpioConnection.Open () [0x00036] in <c4694beda89543a583765d12b492fa36>:0 
  at Raspberry.IO.GeneralPurpose.GpioConnection..ctor (Raspberry.IO.GeneralPurpose.GpioConnectionSettings settings, System.Collections.Generic.IEnumerable`1[T] pins) [0x000f8] in <c4694beda89543a583765d12b492fa36>:0 
  at Raspberry.IO.GeneralPurpose.GpioConnection..ctor (Raspberry.IO.GeneralPurpose.PinConfiguration[] pins) [0x00000] in <c4694beda89543a583765d12b492fa36>:0 
  at RaspiMusic.Program.Main (System.String[] args) [0x0011a] in <774e5be7bcda41d78d9e5b5651299bc9>:0 
[ERROR] FATAL UNHANDLED EXCEPTION: System.NullReferenceException: Object reference not set to an instance of an object.
  at Raspberry.IO.GeneralPurpose.GpioConnection.Allocate (Raspberry.IO.GeneralPurpose.PinConfiguration configuration) [0x00073] in <c4694beda89543a583765d12b492fa36>:0 
  at Raspberry.IO.GeneralPurpose.GpioConnection.Open () [0x00036] in <c4694beda89543a583765d12b492fa36>:0 
  at Raspberry.IO.GeneralPurpose.GpioConnection..ctor (Raspberry.IO.GeneralPurpose.GpioConnectionSettings settings, System.Collections.Generic.IEnumerable`1[T] pins) [0x000f8] in <c4694beda89543a583765d12b492fa36>:0 
  at Raspberry.IO.GeneralPurpose.GpioConnection..ctor (Raspberry.IO.GeneralPurpose.PinConfiguration[] pins) [0x00000] in <c4694beda89543a583765d12b492fa36>:0 
  at RaspiMusic.Program.Main (System.String[] args) [0x0011a] in <774e5be7bcda41d78d9e5b5651299bc9>:0

[mwiedemeyer]

It seems to be an issue with Raspberry.IO.GeneralPurpose. It works with an older raspian version: http://downloads.raspberrypi.org/raspbian/images/raspbian-2016-05-31/
Please see here for details: raspberry-sharp/raspberry-sharp-io#86

[Jim999AGC]

Thank you, problem solved and everything runs fine