Blank boxes indicate that a file used for a view image or conditional format icon is missing. A file that is deleted, moved, or renamed is considered a missing file. Normally, a red x would display in place of missing files; however, in some cases you may see a blank box instead.
Blank boxes and red x’s can be corrected for conditional formats by replacing missing files or updating the conditional format. Blank boxes and red x’s can be corrected for images by replacing the missing file or updating the measure item expression.
See also: Why do Red X’s Show in Views or Conditional Format Windows?
Here is a view with a conditional format on the last measure item.
Here is a conditional format window showing icons selected for each conditional format rule.
The files for the Conditional Format icons were deleted, which results in blank boxes the next time the user runs the view.
The blank boxes also show in conditional format windows, such as the Conditional Format Maintenance window.
The user can select new icons for each rule. Here are the new selections for the rules followed by the updated view reflecting the changes.
