Ever had this problem when using flexible modeling "move" command?
I was pulling my hair out trying to make a seemingly simple change using the flexible modeling extension:
Just as I prepared the above image to post as a question, I discovered the answer:
After the preview shows your geometry in the correct place, add one more constraint to the set - namely, the "Fix" constraint. Then the green check-box will become active and you can save the changes. Please post if you know of a faster and more intuitive way of doing this.