updated version of mscomctl.ocx (mscomctl2017.ocx) will not register

Question

Suddenly when I try to update an application I made in VB6 on users machines, they get this error message when they run the application:

When I try to manually register the .ocx file using "regsvr32 mscomctl2017" command in the \syswow64 directory, I get the same error.

It seems like I'm having compatibility issues with three different version of this control on my development machine.

I currently have 3 version: mscomctl.ocx, mscomctl2014.ocx, and mscomctl2017.ocx.

Is there any way to revert back to an earlier version of the .ocx file that didn't show the error?

Any help would be greatly appreciated. Thanks Paul Wilson

Answer 1

According to Microsoft's Support Statement for Visual Basic 6.0 on Windows mscomctll.ocx is among the supported runtime files that can be distributed with your application. There is no mention of any versions named mscomctl2014.ocx or mscomctl2017.ocx. Further, it says "The supported version of the files is available online on the Microsoft Download Center (https://go.microsoft.com/fwlink/?LinkID=142927)."

So it seems to me that you should update the system you use for VB6 development with the supported versions of the runtime files obtained from Microsoft and redistribute/register those controls on your target systems.

Since we don't know if the registry of those systems was left in an unknown state you may want to try unregistering the existing version of the control as the first step. Naturally, I suggest you create complete backups before taking further action.