In case You wonder; VB6, aka classic VB, is still in use :) Developing VB6 based COM add-ins is still an option, especially when targeting Excel 2000 and onforward.
Microsoft has reported that Office 2013 does not include an important dependency file, Add-in Designer Object Library (msaddndr.dll). If You use the Shared COM Add-in template then You need to distribute this file with the solutions.
For more details please see the blogpost: VB6 based add-ins may fail to work in Office 2013
It’s great that Microsoft actually publishes it but I don’t like the last section of the blog entry:
For the long term, if you are the developer of the add-in, please consider moving to newer supported ways of writing add-ins, such as Apps for Office or VSTO.
It’s obvious that Microsoft try to force us to stop developing with classic VB. Of course, in the long run classic VB is a dead technology as it does not support x64 versions of Office.
The issue is actually two folded. First, VSTO is only maintained and it seems that no more development of it will be made. To be honest, VSTO is a less successful poor development platform and very few developers actually use it. Apps for Office is, at best, in the beta stage and is, at present, of little practical use.
It’s worrying that Microsoft points us to technologies that suffer from various troubles and issues. At the same time Microsoft cut off classic VB; the Shared COM Add-in template is no longer shipped with Visual Studio.NET and does not support any longer Office 2007. In addition, Office does not include important files. Am I supposed to only use VBA? Is VBA future saved? Probably not.
My personal opinion is that Microsoft wants to drop MS Excel as a development platform. Does MS Excel 2013 represent the new era where MS Excel is only an end users’ tool?