Someone else had posted this same issue but in addtion the the skull/quest bug, I now have no attack list. I hit free refresh and and the list showed only one person. I defeated that single player and was awarded 2 SoW but my total did not change.
Then there was nothing on the list. Refreshed again and no list at all. In addition every single time I refreshed yesterday there were no opponents that were higher rank than me to fight. This happened three times. Once I cleared the list and got a new list but no one was higher than me. Then two of the times I have nothing on the list. I have cleared out my revenge list and now have no one to fight.
All of these bugs have only started when I logged out of the game completely. It was the first time I had logged out completely in months. Now I have tons of bugs.