I encountered an issue after an Adobe Creative Cloud CS6 update today (to version 12.2 Build 6006 for Windows) and thought I'd share the solution. (Yes, CS6 is an old product, but I continue to use it and was surprised to see an update.)
ISSUE:
After the CS6 update I discovered there were no Project Seven extensions (or other brand extensions) listed in the 'Insert' OR 'Modify' menus! Opening CS6 Extension Manager, I could see all extensions were still listed there.
SOLUTION:
1) Close Dreamweaver
2) Open Adobe Extension Manger CS6
3) All installed extensions should be listed. Re-check the 'Enabled' checkbox next to each.
4) Open Dreamweaver. The extensions should again appear in the 'Insert' and 'Modify' menus.
Hope that helps someone.
~ Deborah