I've got a problem with Visual Studio Enterprise 2019, it hangs on "Execute Suggested Action" when I use it to add a reference to another project or library.
I've got a problem with Visual Studio Enterprise 2019, it hangs on "Execute Suggested Action" when I use it to add a reference to another project or library.
It's a Visual Studio bug. They are working on it. Take a look here: https://developercommunity2.visualstudio.com/t/Infinite-suggested-action-never-ends/1223055
The fix will be probably released on the next release (16.9).
UPDATE: Still in vs 16.8.4 but should be solved in 16.9.
UPDATE 2: In 16.9 PREVIEW 3, this issue seems to be resolved.
UPDATE 3: Fix has been released! You can download the new version of VS now.
if anyone struggle with adding references: go to your project -> right click on Dependencies -> select eg Add Project Reference -> look for proper reference 
I was having the same issue when adding on the suggestion of Intellisense. For me, it turned out to be an issue of cyclic reference. My bad. I corrected it and now it doesn't hang.
It was VS 2019 community, Windows Forms (C#)