We are VSTO add-ins developers (Visio 2007, Visio 2010, Visio 2013) and have hit a major software issue when we convert a .vdx file to the new .vsdx file format. When opening the converted Visio drawing, with Visio 2013, it keeps adding the Del='1' attribute on some connection points in the Visio drawing which disconnects the shapes.

This problem is intermittent and has pop-up on more than 1 computer although on some other computers this works fine.

I have already posted my issue in MSDN forums; here's the link for reference: https://social.technet.microsoft.com/Forums/en-US/6a43db8a-8339-4568-98b9-4ed999314368/visio-2013-keeps-disconnecting-shapes-by-adding-the-section-nconnection-with-rows-containing-the?forum=vsto

We would love to find some documentation explaining all of the different attributes; the reason why Visio 2013 decides to add them when there have been no change made by the user.

As was identified as a bug by Microsoft, 28692 OfficeQFE, Visio would have a problem when opening SVG(Z) files when not connected to the internet (offline). This bug was hotfixed by Microsoft in this KB 2466309 https://support.microsoft.com/en-us/help/2466309.
Last year, Microsoft rolled out an Update package that affected Visio 2007 and 2010 versions - which makes Visio to connect to the hans-moleman.w3.org website. This behavior introduced a latency/delay of approximately 1-2 minutes. This has affected several of our clients that uses the Visio application to convert SVG(z) file to PNG. Can this behavior be reverted back or simply - remove the behavior for Visio to reach out to the internet through a Registry setting?