Great that now it works!
Now, in the .NET Scripting extension window, click on the tab References. You should see some already included dll files like System.dll, System.Data.dll, etc...
Click on the "..." button below and browse for your dll. When selected click "Add reference".
Now go to the Code tab, and write a function that calls the DLL:
In the Startup object textbox above write the name of the class (in this case "CallDllClass").
public class CallDllClass
public static bool CallDll()
bool bLogAsBatch = false;
bool bLogOnAsService = false;
bool bActAsPartOfOS = false;
string errormsg = string.Empty;
bool bRetVal = false;
bRetVal = InstallerHelper.Helper.CheckUserRights(ref bLogAsBatch, ref bLogOnAsService, ref bActAsPartOfOS, out errormsg);
Try to compile the code clicking on the "Compile" button: if there are no errors you have no problems.
In a MMF event, use the "Call function" action of the .NET Scripting object with these parameters:
Function name: "CallDllClass.CallDll"
I haven't tried with a DLL, but it should work. Otherwise write here what errors you get.