Since when is "size" not allowed as a variation?

[inhawaii]

A listing i've had forever. It comes in 2 variations, small package and large package.

I just sold 3 small packages today. I did a inventory count. Corrected my inventory.

When i tried to save the listing, i get this error message...

Since when is "size" not allowed as  a variation? 

[inhawaii]

Heads up.   This is a confirmed glitch.  At first ebay thought it was a browser issue, but it's not. I used 3 different browsers and got the same error message.