MSCOMCTL.OCX control functionality (which handles the Windows Common Controls 6.0) is not working in MS Access. This handles the treeview control among other ActiveX controls

The MSCOMCTL.OCX library of ActiveX controls is compatible with all 32-bit editions of Microsoft Access. If for some reason it is not working for you, please check the following:

• The MSCOMCTL.OCX library is compatible with 32-bit editions of Microsoft Office *only*. It does not work with 64-bit editions of Microsoft Office. Please be sure that it is the 32-bit edition of Microsoft Office that you have installed.
• We’ve seen some cases where the MSCOMCTL.OCX library is not registered correctly on systems as a result of an issue with the way that a Microsoft Security update was installed. This is a known issue. We’ve posted an article about this issue and we've included the steps to resolve the issue on machines that are experiencing it. This applies to all versions of Microsoft Office (including MS Access) that use this control.