I needed to do some changes to my Office 365 SharePoint using SharePoint Designer. When using SharePoint Designer 2013, every time I tried to use the Open Site dialog, it would crash. SharePoint Designer 2010 (SPD2010) was still working fine not SPD2013.
Solution:
Open the Registry Editor. You can do this by going to the Start menu (I’m still a Windows 7 stalwart, so I can’t vouch for how this might work on Windows 8), choosing “Run”, and typing “regedit” in the Open: box.
Look for the keys:
HKEY_CURRENT_USER\Software\Microsoft\Office\14.0\Common\Open Find\Microsoft SharePoint Designer\Settings\Open Site
and
HKEY_CURRENT_USER\Software\Microsoft\Office\15.0\Common\Open Find\Microsoft SharePoint Designer\Settings\Open Site
In my case, they were identical.
Delete both of the ClientGUID keys. You can do this by highlighting the key and hitting the Delete key or right clicking and choosing Delete.
Once I had deleted these two registry keys, I was able to open sites in both versions of SharePoint Designer with no problems.
