Microsoft.Dynamics.Ax.Xpp.ErrorException "A parameter could not be serialized." when posting document

Hello,

when posting a document (sales confirmation, purchase order) we get the following error message:

Microsoft.Dynamics.Ax.Xpp.ErrorException: Exception of type 'Microsoft.Dynamics.Ax.Xpp.ErrorException' was thrown.

at Dynamics.Ax.Application.SysOperationServiceController.runServiceOperation(Object[] parameters) in SysOperationServiceController.runServiceOperation.xpp:line 22

at SysOperationServiceController::runServiceOperation(Object[] )

at Microsoft.Dynamics.Ax.Xpp.ReflectionCallHelper.MakeStaticCall(Type type, String MethodName, Object[] parameters)

at Dynamics.Ax.Application.SysDictClass.invokeStaticMethod(Object[] _params) in SysDictClass.invokeStaticMethod.xpp:line 26

at SysDictClass::invokeStaticMethod(Object[] )

at Microsoft.Dynamics.Ax.Xpp.ReflectionCallHelper.MakeStaticCall(Type type, String MethodName, Object[] parameters)

at Microsoft.Dynamics.Ax.Xpp.PredefinedFunctions.runAsInvoke(String className, String staticMethodName, Object[] parms, Object[]& exportInfolog)

I have already compiled the whole application with complete CIL-generation aftwards, restarted the complete application server. Nothing helps. In the moment we have removed the check "Execute business operations in CIL" in the user options, then it's possible to post the documents. Has here anybody a tip for me would I could do to get rid of this problem?

Regards
Patrick