On a computer that experiences the problem, the Ref Edit library (refedit.dll) is not available in the references under the VB Editor’s Tools menu,and sometimes it turns up as a MISSING reference in this list.
The Ref Edit library is also not found in the list of Additional Controls which can be added to the VBE’s Controls Toolbox.
If the Ref Edit control had been present on the Controls Toolbox, its place may be taken by a gray square with a tooltip of “Unknown”.
Update 21 September 2012: As I have now taken up a full-time job, I am not taking on any new consulting work but I continue to support existing clients.
I have also started a blog where new articles will be posted.
Because the articles on this site have been in the search engines for a while I will keep the site going as an archive.
It seems to be related to our old friend, the Ref Edit control.
If a workbook or add-in has a User Form with a Ref Edit, this error may occur.
When the error occurs, it may be impossible to view the User Form in the VB Editor, or if the User Form can be viewed, any Ref Edits have been stripped off the form.User Forms without Ref Edit controls can be viewed with no problems.In recent months I have encountered a particularly troublesome error.It occurs in Excel 20 (and perhaps in earlier versions, but I don’t recall any such cases).The error is heralded by an unusually unhelpful error message, even my Microsoft’s standards: error: Sometimes these occur once, sometimes twice, when Excel is started, when a workbook with code is opened, or when an add-in is opened.Association with Ref Edit Controls Closer examination sheds some light on the problem.