Screenshot
Steps to reproduce:
1.Go to this page:http://en.wikipedia.beta.wmflabs.org/wiki/14thmaychrome?veaction=edit
2.Select the image on the page
3.Go to Media Settings>Advanced Settings>Image Size
4.Change the tab from Default to custom or Custom to Default
Observed Result:
The "Make full size" button remains disabled for the image
See the screenshot attached
Version: unspecified
Severity: normal
Attached: