I am having exactly the same problem, running 8.5.2FP2
I followed the instructions. I have installed dojo 1.5.0, 1.5.1 and 1.6.1. Regardless of version, I get a gray box. Happens in Chrome, IE9 and Firefox.
I am not seeing any errors in firebug.
running dojo.addOnLoad Function
Setting Up Properties
Clearing Selected Files List
Creating Upload Button
Connecting To Required Fields
Connecting To Upload onChange Event
Connecting To Upload onCompleteEvent
initializing flash...
.............PARAMS: <a class="objectLink objectLink-object a11yFocus ">Object { ds={...}, dn={...}, more...}</a></div>
no files in queue
*SWF Loaded. isDebug: true devMode:false
* Flash Uploader Toggle Disable:: true
I'd really love to use this app, but I have already spent a day trying to figure this out...