Cannot convert null to 'int' because it is a non-nullable value type

Hello Support

We have updatet CloudPanel from 3.0.x to 3.1.1536 over the Migrationversion 3.1.0030.
After the Update we have two Erros. One Error we fixed with P20160513_159.
Another Error is, when we click off Companies in the left Pane, then list all Companies in the middle Pane.
When we then click off a Company, whith activated Exchange we get a Runtime Error.
When Exchange for the Company is not activeted works fine.
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Server Error in ‘/CloudPanel’ Application.

Cannot convert null to ‘int’ because it is a non-nullable value type
? Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

?Exception Details: Microsoft.CSharp.RuntimeBinder.RuntimeBinderException: Cannot convert null to ‘int’ because it is a non-nullable value type

Source Error:

?An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.?

Stack Trace:

[RuntimeBinderException: Cannot convert null to ‘int’ because it is a non-nullable value type]
?? CallSite.Target(Closure , CallSite , Object ) +153
?? RazorOutput.RazorView.Execute() +101127
?? Nancy.ViewEngines.Razor.NancyRazorViewBase`1.ExecuteView(String body, IDictionary`2 sectionContents) +123
?? System.Dynamic.UpdateDelegates.UpdateAndExecuteVoid3(CallSite site, T0 arg0, T1 arg1, T2 arg2) +467
?? Nancy.ViewEngines.Razor.<>c__DisplayClass9_0.<RenderView>b__0(Stream stream) +851
?? Nancy.Hosting.Aspnet.<ProcessRequest>d__2.MoveNext() +381
?? System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) +13891908
?? System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +61
?? System.Web.TaskAsyncHelper.EndTask(IAsyncResult ar) +69
?? System.Web.CallHandlerExecutionStep.OnAsyncHandlerCompletion(IAsyncResult ar) +178

Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.6.1085.0

There for the error, a solution