Hi,
since yesterday's Firefox update to version 48.0 my client libraries (JS) stopped working.

The error we get back is:
Error: Permission denied to access property "LS_e"

Client library version: 5.0 (JavaScript)

I found out from the forum that the problem could be caused by domain / host setup, but I think we have the correct setup:
domain: *****.org
LS_Host: push.*****.org

Can the problem be caused by a bug in Firefox update?
Any ideas?

Thank you
4 days later
Hi enrico,

I confirm that we are investigating the issue directly in touch via support.

Regards,
Giuseppe
I can confirm that the issue is due to an unusual behavior introduced by Firefox 48.0 that concerns document.domain set on iframe/parent when coming from different ports.
The behavior is also explained here: https://bugzilla.mozilla.org/show_bug.cgi?id=1292522 .
In case of Lightstreamer client lib 5 (or lower) the only workaround viable is to uniform the port number between web and lighstreamer servers.

I also confirm that JavaScript library 6 or newer is not affected by the problem since totally different techniques are used.