[wix-users] Error starting custom action

[Kirti Bauer]

I had an installation created by using WIX 3.11 in Visual Studio 2017. Until now I have had no major issues with the installation and the custom actions library.
My current installation site is a Windows 2016 Server running .NET Framework v4.0.30319.

My MSI works until the first access to a custom action.

I created a simple custom action function that presents the user with a dialog box and returns the success result.
[CustomAction]
public static ActionResult Test(Session session)
{
session.Log("Test started");
MessageBox.Show("Test");
session.Log("Test ended");
return ActionResult.Success;
}

Using verbose logging I get the following error:

MSI (c) (50:B4) [16:33:41:039]: Doing action: Test
Action 16:33:41: Test.
Action start 16:33:41: Test.
MSI (c) (50:38) [16:33:41:039]: Invoking remote custom action. DLL: C:\Users\SVC_AB~1\AppData\Local\Temp\2\MSI1E2A.tmp, Entrypoint: Test
MSI (c) (50:E4) [16:33:41:055]: Cloaking enabled.
MSI (c) (50:E4) [16:33:41:055]: Attempting to enable all disabled privileges before calling Install on Server
MSI (c) (50:E4) [16:33:41:055]: Connected to service for CA interface.
SFXCA: RUNDLL32 returned error code: -1
CustomAction Test returned actual error code 1603 (note this may not be 100% accurate if translation happened inside sandbox)
Action ended 16:33:44: Test. Return value 3.
MSI (c) (50:B4) [16:33:44:717]: Doing action: FatalError
Action 16:33:44: FatalError.
Action start 16:33:44: FatalError.
Action 16:33:44: FatalError. Dialog created
MSI (c) (50:64) [16:33:44:748]: Note: 1: 2731 2: 0
Action ended 16:33:46: FatalError. Return value 2.
Action ended 16:33:46: INSTALL. Return value 3.

What does the error code -1 mean from the rundll32?
I have searched for this error but have found no results.

Any help would be appreciated.

BR
kibau