LiveReload is currently enabled but could not be loaded.

This is a new error message which was added in 4.3. The error itself is not new though. Previously it was not visualized though. Previously you would just see a red message in the Console e.g. in Chrome Inspector telling you that livereload.js could not be loaded. To prevent an actualy error in the browser we now check before including that file if it can even be loaded. So: The message just means that livereload.js can't be loaded (LiveReload is enabled in the theme settings but not working because Guard is not running). Fix: Run Guard or disable LiveReload.

I would also add that this fixed it for me. To add onto what Fubhy said, navigate into your theme's folder via your CLI (Terminal, et.al.) and run this command:
$ drush omega-guard

Once this is run, you should be OK.

Guard-livereload 2.* will fail silently if the default port (35729) is taken.

ok

Actually I am seeing this message a lot recently. Guard running correctly. Anybody else?

I am working omn a macbook pro and find that a reboot fixes the problem but only temporarily

@MrPaulDriver try to find out what's running on port 35729 (or whatever port you've set livereload to use).
You can use netstat or losf in terminal:

netstat -anp tcp | grep 35729
lsof -i tcp:35729

If it's not the livereload process, kill it.

Terminal doesn't return anything. I guess this means nothing has been traced?

If both commands don't return anything there is no process listening on this port.

Thanks. Still don't understand why it is dropping out though.

Revisiting this as I still have the problem more often than not of Livereload not working. Now I am seeing other processes in play. No sure where to go from here. Any pointers?

tcp4       0      0  127.0.0.1.35729        127.0.0.1.50697        ESTABLISHED
tcp4       0      0  127.0.0.1.50697        127.0.0.1.35729        ESTABLISHED
tcp4       0      0  *.35729                *.*                    LISTEN    

lsof

COMMAND    PID       USER   FD   TYPE             DEVICE SIZE/OFF NODE NAME
Google     322 pauldriver  230u  IPv4 0xcad3656bd34d4d5f      0t0  TCP localhost:50697->localhost:35729 (ESTABLISHED)
ruby      2575 pauldriver    7u  IPv4 0xcad3656bcc8ddeff      0t0  TCP *:35729 (LISTEN)
ruby      2575 pauldriver    9u  IPv4 0xcad3656bcc8e023f      0t0  TCP localhost:35729->localhost:50697 (ESTABLISHED)

Perhaps you've started the livereload plugin via omega development settings and command line (drush ogrd) simultaneously?

My understanding is that the development settings for Livereload need to be enabled for drush ogrd to work.

Not quite: drush omega-guard starts a live reload server. So does omega development extension. You should be able to run either one.
What you need is: a) drush ogrd livereload or omega developer extension livereload as a server and b) browser livereload plugin as a client. The browser plugin connects to the server and makes sure the browser is reloaded if the livereload server instructs it to. Guard monitors your theme directory for file changes and runs sass to regenerate the css.

Thank you for taking so much time with me Bas.

I have always had Livereload browser plugin disabled as I read somewhere that it conflicts with drush ogrd. I normally have Omega dev settings enabled and then run drush ogrd and usually find that everything works. It is only recently that I have started to have problems.

I tried today, disabling livereload developer settings in Omega, running drush ogrd and enabling Livereload Chrome plugin. This also appears to work for me. I'll try this for a while and see how I get on.

excellent... happy theming!

This is a user specific issue, so let's close it.