CtagsSideKick has an interesting history. Before, there was CodeBrowser plugin and I asked the author to please turn it into a proper SideKick plugin. So he did, and we called it CTagsSideKick, and you can't download CodeBrowser anymore because it is no longer maintained. I like CtagsSideKick much better because we don't need another dockable to use it. My SideKick dockable has 16 parsers. I use it for showing me a structure browser in any language.
CtagsSideKick has an interesting history. Before, there was CodeBrowser plugin and I asked the author to please turn it into a proper SideKick plugin. So he did, and we called it CTagsSideKick, and you can't download CodeBrowser anymore because it is no longer maintained. I like CtagsSideKick much better because we don't need another dockable to use it.
Why would someone use this instead of CtagsSideKick?
Also, please clear the activity log, reproduce, and then attach the activity log to this ticket.
We need more info to reproduce. Is a username/password required for this proxy? Did you supply one or both or neither?
Under jEdit global options - Proxy Settings, are you using a proxy server? The error message tells you to supply a password there. If you are not using a proxy server, be sure to uncheck that option.
To sort the buffer sets (which are used by BufferTabs) global options - view - sort buffer switcher.
Are you talking about the BufferTabs plugin? jEdit has no tabs.