Central Queensland Linux User Group

Problem :-

Firefox web browser unable to install addons.

Error message produced:

Firefox could not install the file at

"https://addons.mozilla.org/en-US/firefox/downloads/latest/3006/addon-3006-latest.xpi?src=addondetail"

because: Download error
-228
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Fix:-

Disable IPv6

(1) Open the file /etc/sysctl.conf as sudo in an editor and add the following lines at the end of the file:

#disable ipv6
net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1
net.ipv6.conf.lo.disable_ipv6 = 1

Save the file

(2) Open Firefox and in the URL address box enter:

about:config

Click "I'll be careful"

Type ipv6 in the filter box to get to the one and only line that's needed; it will read:

network.dns.disableIPv6 default boolean false

The default value is "false"; double-click to set the value to "true" (to disable IPv6):

network.dns.disableIPv6 user-set boolean true

Close Firefox

(3) Reboot the computer

To check that IPv6 has actually been disabled, in a terminal enter the following and press enter:

cat /proc/sys/net/ipv6/conf/all/disable_ipv6

A return of 0 means it is enabled and a 1 means disabled.

Firefox should now accept the installation of addons.