File upload not working on the first open to browse/select. Any button, select or close action will only flash/refresh/reopen the file browser, after that it works OK as it normally does.

We use the same code as from http://www.zkoss.org/zkdemo/file_handling/file_upload

<zk>
<button label="Upload Image" upload="true,maxsize=300">
<attribute name="onUpload"><![CDATA[
org.zkoss.util.media.Media media = event.getMedia();
if (media instanceof org.zkoss.image.Image)

{ org.zkoss.zul.Image image = new org.zkoss.zul.Image(); image.setContent(media); image.setParent(pics); }

else

{ Messagebox.show("Not an image: "+media, "Error", Messagebox.OK, Messagebox.ERROR); break; }

]]></attribute>
</button>
<separator />
<vlayout id="pics" height="360px" style="overflow:auto" />
</zk>