I came across this error going through my site. I noticed that the upload button was missing when it used to be there before I installed 2.0 build#32 (beta44). In the template, the part that should be something like:
<div class=body>%upload-link%<br><br>%up%%files%<br></div>
is missing the %upload-link% part. I stuck it in and everything was as it should be.
A good idea would be to check out the wiki that deals with the template page (
here) to make sure you got everything you want on your site.
Hope this helps.