Index: wp-includes/media.php
===================================================================
--- wp-includes/media.php (revision 22967)
+++ wp-includes/media.php (working copy)
@@ -1660,7 +1660,7 @@
{{ data.filename }}
{{ data.dateFormatted }}
- <# if ( 'image' === data.type && ! data.uploading ) { #>
+ <# if ( 'image' === data.type && ! data.uploading && data.width && data.height ) { #>
{{ data.width }} × {{ data.height }}
<# } #>
<# if ( ! data.uploading ) { #>