Unbalanced quotes in the JSON input ...
I was able to reproduce the problem with
a variation of your input. To fix it I escaped the quotes surrounding
the file name. See the bold text below:
{
"contentType":"image/vnd.dwg; name=\"Drawing12.dwg\"",
"contentID":"<1__=4CBBF75EDFB8107C8f9e8a93df93869091@local>",
"contentDisposition":"attachment; filename=\"Drawing12.dwg\"",
"data":"<data>",
"boundary":"--0__=4CBBF75EDFB8107C8f9e8a93df938690918c4CBBF75EDFB8107C"
}
Hope this helps.
-- Dave