I entered this yesterday in response to another inquiry on this subject. It may help some.
I don't know if it will work for everybody but it should work for some. It works for me.
I've having the same problem starting yesterday. Can't edit, relist, or anything.
Here's how I'm getting around this glitch until they fix it.
Click up more than one item... (filling in those little squares) - the one you want to work on and another.
The multi-item grid should come up.
Make what ever changes you want on the desired item.
Remove the "extra" dummy item.
Hit "SUBMIT" button.
I hope this helps. It takes just a few seconds longer.. but at least it works.