Plex 2E

When I open the panel for a WinC function, I get the following warning:

How can one fix this kind of error and stop the warning message from displaying? I believe the component can be registered using an ocx file but I don't know which contains this control and where the file can be found.

The component is displayed in the panel like this:

My operation system is 64-bit Windows 8.1.

Toolbar 5.0 is part of comctl32.ocx. Place it into SysWOW64 Folder and register.

ActiveX - Stella Tools (CA Plex Developer Tools)

The warning went away after I registered the comctl32.ocx file. I found the file in the installation package on page https://www.microsoft.com/en-us/download/details.aspx?id=5721

The comctl32.ocx file was included in file comctl32.cab. I extracted the file comctl32.ocx and placed it in c:\windows\syswowy64 and as administrator typed "regsvr32 comctl32.ocx".

Both answers were correct, but I marked George's one as the answer because it showed more detailed information about the solution.