Compile error in hidden module

Applies to versions of MerlinXL designed to run on Excel 2003.

Error Message

When opening older versions of MerlinXL  in a 64 bit OS you see the error message:

Compile error in hidden module

Example Error Message


This error is generally caused by an out of date version of MSCOMCTL.OCX

This file can be found in C:\Windows\SysWOW64

File dates before June 2012 are out of date and should be updated:



Use Excel 2010 or later.

Excel 2007 or earlier is no longer supported

Upgrade the version of MerlinXL to v2



Old Solution

Solution – Requires Local pc admin rights

1. Locate a pc in your organisation that does have an up-to-date  version of the OCX file:

C:\Windows\SysWOW64\MSCOMCTL.OCX dated on or after June 2012.

2. Copy this file and transfer it to the desktop of the affected pc

3. On the affected pc ensure Excel is closed and open CMD.exe (Run as administrator)

4. Unregister the existing OCX file using:

C:> regsvr32.exe /u C:\Windows\sysWOW64\MSCOMCTL.OCX

5. In File Explorer rename the file to  C:\Windows\SysWOW64\MSCOMCTL.OCX.OLD

6. Copy the new ocx file from the desktop to the C:\Windows\SysWOW64 folder

7. In the cmd window reregister the ocx file with:

C:> regsvr32.exe C:\Windows\sysWOW64\MSCOMCTL.OCX

Open MerlinXL and check that the problem is resolved.

If you receive the error message:

Could not load an object because it is not available on this machine