The title of this post is pretty self explanatory, but I thought it worth mentioning since I had never run across this rule until just recently.  A few weeks ago I was testing out a new workflow attached to a SharePoint 2007 document library.  I uploaded various file types to ensure all were handled properly.  One of the files I happened to test with was an empty .txt file to which I got the following error.

     As you can see from the error message you aren’t allowed to upload a file that is empty.  Fast forward to this week when I was doing some research for my upcoming SharePoint 2010 beta exams.  I remembered that error I got a few weeks ago and decided to try out with SharePoint 2010 as well.  No surprises I got a similar error.

Conclusion

    Next time you are uploading files to a SharePoint 2007 or 2010 document library, make sure the file is not empty.  Coincidentally when I tweeted about this issue a few friends replied that they had also found this error recently.  I don’t know the internal reasoning why this is prevented but I assume it has something to do with how the blob for the file is stored in the database.  I assume that this would still be the case even if you had Remote Blob Storage (RBS) configured for your farm, but don’t have access to such a farm to confirm.  If anyone reading this does have access and wants to confirm that would be appreciated, just leave a comment.

      -Frog Out