Strange stack trace in Windows Phone 8

Hi I have a Windows phone app which is getting a number of crashes reported by the dev center. I recently did an upgrade which included some minor changes and the moving of some common code from a Silverlight class library to a Windows phone class library (so that I could open the project in VS2013).
No issues in all my testing in the emulator and on the phone.

A fair number of the crashes seem to be in the background agent generating a tile.. not obvious why but I can at least see which method in my code (not sure how to use the offet to find the exact line.

However the bulk of me errors are error E06D7363 errors with the following stack trace. (have to reduce as ist too big to include fully) Nothing in here that remotely looks like my code so I have no idea where to start.

Any ideas to pint me in the right direction?

thanks.

Frame    Image                     Function                                                                                                                                                                                                                                                                               Offset        
0        headlesshost              __ImageBase                                                                                                                                                                                                                                                                            0x00000007    
1        coreclr                   CLRException::HandlerState::SetupCatch                                                                                                                                                                                                                                                 0x00000075    
2        coreclr                   Module::DoInit                                                                                                                                                                                                                                                                         0x00000275    
3        msvcrt                    __CxxCallCatchBlock                                                                                                                                                                                                                                                                    0x00000077    
4        msvcrt                    _getpid                                                                                                                                                                                                                                                                                0x00000608    
5        coreclr                   __dyn_tls_init_callback _PERF_                                                                                                                                                                                                                                                         0x00000000    
6        coreclr                   CAssemblyLocation::`vftable'                                                                                                                                                                                                                                                           0x0007aa44    
7        coreclr                   CAssemblyLocation::`vftable'                                                                                                                                                                                                                                                           0x0007aa1c    
8        coreclr                   Module::DoInit                                                                                                                                                                                                                                                                         0x00000133    
9        coreclr                   Module::DoInit                                                                                                                                                                                                                                                                         0x00000001    
10       msvcrt                    __piob _PERF_                                                                                                                                                                                                                                                                          0x00000000    
11       ntdll                     __PchSym_ _PERF_                                                                                                                                                                                                                                                                       0x00000000    
12       coreclr                   SString::ConvertToUnicode                                                                                                                                                                                                                                                              0x0000002d    
13       coreclr                   Module::DoInit                                                                                                                                                                                                                                                                         0x00000131    
14       msvcrt                    _CallSettingFrame                                                                                                                                                                                                                                                                      0x00000011    
15       msvcrt                    __CxxCallCatchBlock                                                                                                                                                                                                                                                                    0x000000b1    
16       ntdll                     RcConsolidateFrames                                                                                                                                                                                                                                                                    0x00000005    
17       ntdll                     RtlUnwindEx                                                                                                                                                                                                                                                                            0x000001d3    
18       coreclr                   operator new                                                                                                                                                                                                                                                                           0x00000011    
19       coreclr                   PEImage::s_hashLock                                                                                                                                                                                                                                                                    0x00000000    
20       coreclr                   PEImage::Release                                                                                                                                                                                                                                                                       0x00000091    
21       coreclr                   BINDER_SPACE::AssemblyBinder::BindToSystemSatellite                                                                                                                                                                                                                                    0x000000d1    
22       ntdll                     RtlUnwindEx                                                                                                                                                                                                                                                                            0x00000001    
23       msvcrt                    _UnwindNestedFrames                                                                                                                                                                                                                                                                    0x00000069    
24       msvcrt                    __CxxCallCatchBlock                                                                                                                                                                                                                                                                    0x00000001    
25       coreclr                   CAssemblyLocation::`vftable'                                                                                                                                                                                                                                                           0x0007aa30    
26       coreclr                   CAssemblyLocation::`vftable'                                                                                                                                                                                                                                                           0x0007aa08    
27       msvcrt                    FindHandler                                                                                                                                                                                                                                                                            0x0000026f    
28       coreclr                   Module::DoInit                                                                                                                                                                                                                                                                         0x0000011b    
29       coreclr                   CTA2PAVException                                                                                                                                                                                                                                                                       0x00000008    
30       msvcrt                    _getptd_noexit                                                                                                                                                                                                                                                                         0x0000001b    
31       msvcrt                    __InternalCxxFrameHandler                                                                                                                                                                                                                                                              0x00000155    
32       msvcrt                    __CxxFrameHandler3                                                                                                                                                                                                                                                                     0x00000043    
33       coreclr                   CAssemblyLocation::`vftable'                                                                                                                                                                                                                                                           0x0007ab00    
34       ntdll                     RtlpExecuteHandlerForException                                                                                                                                                                                                                                                         0x00000009    
35       ntdll                     RtlDispatchException                                                                                                                                                                                                                                                                   0x0000015d    
36       coreclr                   _CxxFrameHandler3                                                                                                                                                                                                                                                                      0x00000001    
37       coreclr                   ExceptionHijack_xdata_end                                                                                                                                                                                                                                                              0x0001b3ec    
38       coreclr                   LoaderHeap::RealAllocMemUnsafe                                                                                                                                                                                                                                                         0x00000001    
39       kernelbase                __ImageBase                                                                                                                                                                                                                                                                            0x00000000    
40       kernelbase                __PchSym_ _PERF_                                                                                                                                                                                                                                                                       0x00000000    
41       msvcrt                    __sbh_initialized                                                                                                                                                                                                                                                                      0x00000000    
42       msvcrt                    __piob _PERF_                                                                                                                                                                                                                                                                          0x00000000    
43       coreclr                   __dyn_tls_init_callback _PERF_                                                                                                                                                                                                                                                         0x00000000    
44       coreclr                   __dyn_tls_init_callback _PERF_                                                                                                                                                                                                                                                         0x00000000    
45       coreclr                   __dyn_tls_init_callback _PERF_                                                                                                                                                                                                                                                         0x00000000    
46       coreclr                   __dyn_tls_init_callback _PERF_                                                                                                                                                                                                                                                         0x00000000    
47       coreclr                   __dyn_tls_init_callback _PERF_                                                                                                                                                                                                                                                         0x00000000    
48       sechost                   lsalook__MIDL_TypeFormatString                                                                                                                                                                                                                                                         0x000001e2    
49       rpcrt4                    NdrConformantVaryingArrayUnmarshall                                                                                                                                                                                                                                                    0x00000045

<output removed here >    

96       coreclr                   BaseAssemblySpec::CloneFields                                                                                                                                                                                                                                                          0x00000047    
97       coreclr                   __ClrAllocInProcessHeap                                                                                                                                                                                                                                                                0x00000000    
98       coreclr                   EEHeapAllocInProcessHeap

In your case finding the Solution would be needed lots of surfing through sites and Search for the Description of Error codes and find solution for it or You can simply Analyze crash reports. you’ll receive a certification report that contains additional files that you can use to identify what happened. Depending on the type of error that occurred, you’ll receive either A crash dump file or An ErrorInfo file. To examine these files, Dev centre recommend that you use either Microsoft Visual Studio or the Windows Debugger Tools. Have Look over here Analyzing crash reports and Improving apps with Quality reports. Hope this help you out.