Missing DBCOMM.dll ?

I have a simple form with 2 buttons. By pressing Switch I expect to toggle the Serial RTS line.
I have DBCOMM.dll in the folder with app. and added it as a component.
I have also added the Serial library for both device and desktop, ready.
The first line gives the error that it cannot find the DBCOMM.dll.
What stupidity have I committed please?
I am trying to control the line as part of a TimeLapse system to operate my camera.

Sub App_Start
PortEx.New2(1, 9600, "N", 8, 1)
PortEx.PortOpen=True
Form1.Show
End Sub

Sub Switch_Click
PortEx.RTSEnable = Not( PortEx.RTSEnable)
End Sub

Sub Exit_Click
PortEx.PortOpen=False
End Sub

You don't need Dbcomm.dll, it's only for use with the original Serial (not Serial2) libraries and even then you don't need to add it as a component.

I am relieved to hear that, but why then the error and why does the form not show?

[Edit] I got the error before adding DBCOMM.dll, I did that as a result.

[Edit 1] Baffled! I just closed B4PPC, restarted and the error is not there. Sorry for inconvenience, but I know not why.