Pronto (flash) cannot display doc and image in browser

Frédéric Boudaud <[email protected]> Wed, 12 Oct 2016 19:47:42 +0200
Newsgroups gmane.mail.cgatepro.general
Message-ID <[email protected]>
Hello all,

I have a problem downloading or displaying documents in browser. (Chromium 
or firefox)
When using the Pronto flash (installed under linux) firefox says "can't 
display image because it contains some errors" with this URL: 
https://**************/Session/2261-8vPgVG5IM60SlQ6RZJvp/MIME/INBOX-Mail-0/23729-02-B/DSC_7337-FR%-35x45mm.jpg

I have seen in the log file : HTTPU-012059([192.168.0.2]:55613) rsp(0): 550 
unknown session

It works with the standard web interface, with Pronto flash in browser and 
Pronto HTML 5.

Any ideas ?
Fred