I answer the question of versoine Spark 2.6.3 for OSX and LinuxUbuntu ... still does not work file transfer ...
I'm trying with two windows 7 and Spark 2.6.3 client with the server openfire on UbuntuLinux .. everything works but will not let me exchange it nen photos and documents there is no button for attachments leave me alone chat between people ... I would like to use it in the office also to exchange documents ... I do not know what to do ... of the two windows7 I opened the firewall, both incoming and outgoing but nothing .. anyone know how I can do thanks