This problem occurs in rare circumstances with version 4 builds of FileUp prior to version 4.0.8. Certain combinations of original file size and the chunk size being read by IIS cause File up to drop 32,868 bytes from an uploaded file.

Symptoms of this behavior include:

• Some file types will appear "corrupted."
• Simple text files may still open in text editors and only seem to be missing text. For example, a corrupted XML file may only show signs of corruption when an XML editor gives an error that the document is not "well-formed".
• Confirm that the above symptoms are the results of this bug by checking the original (client-side) file size against the uploaded (server-side) file size. The file will always be smaller on the server.
• Not all uploads are affected by this behavior, so the symptoms may be erratic.