J. Paul Getty was an American industrialist and founder of the Getty Oil Company. After becoming one of the richest men in the world, he was approached by an American magazine to write an article describing his success. He was offered a sizable sum of money in return. The magazine said that the article could be of any length. J. Paul Getty accepted their offer and wrote: "Some people find oil. Others don't."
If you see a "The requested DWF is not valid." error message and wonder what happened, keep two things in mind.
Recall how Project Freewheel works. A copy of your DWF file is uploaded to the Project Freewheel server. If something unexpected happens during this process, the resulting file that lands on the server may not be intact. Though this rarely happens, it is normally the result of internet file transfer issues and has nothing specifically to do with Project Freewheel itself. For example, it does not mean that the Project Freewheel server is being overloaded.
Project Freewheel is a technology preview. We know we have problems to work out and bugs to fix. We don’t pretend that this is a production level solution yet. At the same time, we welcome continued usage and hearing about the problems/bugs/ideas/successes people have with the project.
Such is the case with the Project Freewheel Viewer. To paraphrase J. Paul Getty: "Some DWF files work. Others don't." Actually most DWF files work.
For the latest information on Project Freewheel, see Scott Sheppard's It's Alive in the Lab blog.