This malloc occurs quite frequently right after a scene change is attempted. I have a regular camera and an AR camera in the scene. Only one is active at a time. The error dump below is for iOS but Android crashes similarly upon scene change as well.
Trackable kklogoqr lost
(Filename: /Applications/buildAgent/work/b0bcff80449a48aa/Runtime/ExportGenerated/iPhonePlayer-armv7/UnityEngineDebug.cpp Line: 43)
appname(1172,0x3f6ec48c) malloc: *** error for object 0x217b650: pointer being freed was not allocated
*** set a breakpoint in malloc_error_break to debug