Redmine

1. Open the wiki edit page.
2. Upload an image file (e.g. imagefile.png) but do not save.
3. Insert thumbnail macro.
   e.g:
   

   {{thumbnail(imagefile.png)}}
   

4. Show preview.
5. Thumbnail is not displayed and error message is displayed, like this:
   

   Error executing the thumbnail macro (Attachment imagefile.png not found)
   

   
   

(After saving the wiki, the thumbnail will be displayed without any problems.)