I am getting the error: 'Enter a valid value' when I change the icon property of a Sitemap area to an icon that definitely exists.
For example there are 2 icons in the same location called PreEntry32x32 and PreEntry85x57, the icon field accepts the current value of: $webresource:sample_Icons/PreEntry32x32 but won't accept me trying to change it to $webresource:sample_Icons/PreEntry85x57.
Any ideas?