The following are solutions have been worked out by others and may work for you but first clear your browser's cache then:
Solution 1
1. go to orders > all orders
2. click on open orders
3. sort by date (oldest first)
4. select all the old orders that you need to get rid of
5. actions > unarchive orders
6. REFRESH your browser
7. select all the orders again
8. actions > fulfill orders
9. REFRESH your browser
10. I think the orders stayed selected this time, but if not select them all again
11. actions > archive orders
12. REFRESH your browser
=============================================
Solution 2
Once you archive the order, hit "F5" on your keyboard and it force refreshes the page. I notice this works more then hitting the refresh button on the browser.
Edit: to clarify; When you archive an order the # on the order tab on the side will not always change or updated. By hitting the "F5" key. It force refreshes the page which then picks up the change in active orders.
========================================================
Advice from Nick at Shopify.
So going forward you're going to have to account for those orders that note that status now. If you cancel and order or refund it in future, make sure to hit fulfill before doing so to change the status. Once cancelled it will then keep the fulfilled status. If you do not hit the fulfill button on an order, then it is unfulfilled. As such, the behaviour you are seeing is expected, as the order is not fulfilled, and it never will be as you cancelled it before hitting fulfill.
Nick then gives a very long reply on page 3 of this thread with an imbedded image - suggest you try to read this but for me it made my eyes glaze over
===============================================================
