"The index.xml file is missing"
I am unable to open a Numbers file. I get the "The index.xml file is missing" window. I see that this has happened a lot on Pages and some on Numbers. Trying all the recommendations posted here and other places, none of them work. I could open the file with Numbers 2.1. I pulled an older copy of the file from Time Machine and tried to open it with Numbers 2.1, but I get the same result. How very odd. I've also tried Numbers 1.0.3, to no avail.
Using "Show Package Contents" I can see this:
I've tried unzipping the index.zip fike, does not help.
I hope someone has some suggestions. Thanks in advance.