I migrated my Plone site to 5.0.6 and when I changed my theme base from existing customized theme which I was using in earlier plone version to Sunburst from advanced settings in theme tab it started giving me errors and not allowing me to login to the plone site. Reference for error 4097.
Is there a way to revert the changes from back-end because I am not able to login to my server.
This is connecting via SSH to your site (which I'm assuming you've done before and have access to do so), but this is also binding the port to your local machine so you can access it in your browser with localhost
For a bit more information on this command, @varunmicro:
The -L flag to the ssh command binds takes an argument in the form of [address:]port:host_address:host_port and creates a secure "tunnel" from the [address:]port on your local machine to the host_address:host_port on the remote machine.
In the form that @cdw9 gave above, this means that there would be an ssh tunnel created from your local machine to the server that serves website.com. The tunnel would be available on your machine at port 8080 and would connect directly to localhost:8080on the website.com server.
This is useful because your Plone website is being served by a Zope application server which is set to listen to localhost:8080 by default. If you've changed your configuration, you may need to alter either the host address or host port values.
Once you've opened this tunnel (leave the terminal where you ran the command open), you'll be able to load http://localhost:8080 in your web browser, and you should see the Zope root page displayed. This page is not touched by either Plone theming or by Plone security. From there you can go to /manage and enter a Zope admin username and password to get authenticated access to your website.