Fatal error: can't find next separator error

Problem Description

When uploading files accompanied by a large amount of text data using IE 5.0 with AspUpload, the following error may occur:

Persits.Upload.1 (0x800A000E)
Fatal error: can't find next separator.

Solution

Apparently, IE 5.0 has a bug which sometimes generates multipart/form-data POSTs incompatible with RFC 1867, however no official confirmation of this bug was ever found at the Microsoft web site.

The problem is intermittent and seems to occur more often as the amount of text data posted increases. The "bug" is believed to be introduced by IE 5.0 and fixed by IE 5.5.

This error may also occur under IE 5.5 if you use client-side JavaScript to submit your multipart/form-data form.

This problem does not occur with AspUpload 3.0 (and higher).