Powershell – Connect-MsolService Error : Method not found

Problem

After installing Azure Active Directory Powershell module, you will get the following error when you connect Azure AD using the cmdlet Connect-MsolService.

Connect-MsolService : Method not found: 'Void
System.Runtime.InteropServices.Marshal.PtrToStructure(IntPtr, !!0)'.
At line:1 char:1
+ Connect-MsolService -Credential $cred
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : OperationStopped: (:) [Connect-MsolService], Mis
   singMethodException
    + FullyQualifiedErrorId : System.MissingMethodException,Microsoft.Online.A
   dministration.Automation.ConnectMsolService

Fix/Solution

For me the issue was fixed after update my .NET to 4.5.2.

You can also try other solutions if the above update does not fix the problem for you. Check this Microsoft forum for more info: Problem to Connect MsolService