objc_msgSend() selector name: retain CRASH

[GoogleCodeExporter]

What steps will reproduce the problem?
1. randomly take your app to background (while a call session exists)
2. you open the app and you app is crashed
3.

What is the expected output? What do you see instead?
The app crashes when coming back to foreground (see the crash report attached). 

What version of the product are you using? On what operating system?
doubango r1262  
iOS 8.1
iPhone 4s/5s/6

Please provide any additional information below.
it crashes for: 
if(![NgnAVSession hasActiveSession]){

please refer to attached screenshot of crash report

Original issue reported on code.google.com by [email protected] on 30 Apr 2015 at 11:28

Attachments:

• retain-crash.png

[GoogleCodeExporter]

Original comment by [email protected] on 30 May 2015 at 8:46

• Changed state: Accepted