I can not modify the Property values of my AddIn. It is necessary to find the
right add-in (For Each ad In Application.AddIns...)

For some reason, Excel has added one, two or three times a r-like symbol at
the end of the Name, Title, Author, Subject values of my AddIns in the
Watches window. So when comparing the addins (If ad.Title = DATEADDIN Then
....) the addin is not found.

These symbols are not shown on other places, like the Immediates window or
in the Workbook properties, when viewed.

I tried to modify it by making the Add-in back to a Workbook or by running
the following code:
ThisWorkbook.BuiltinDocumentProperties.Item("Title ").Value = "Date XP Add-in
v2.08"

It seems to have an effect on the Immediates window:
? ThisWorkbook.BuiltinDocumentProperties.Item("Title ") .Value
Date XP Add-in v2.08

But the Watches window still shows the original value.

Can someone help?

--
Best regards,
Thierry H.