sjj1805 wrote:Unfortunately still no sidebar.
That is incredibly odd because I can't think of anything that would affect the way your sidebars are displayed other than the theme, and I know for a fact that sidebars work with 2k11 and PHP 7.x.
Your theme does not, by any chance, use custom sidebars (i.e. other than left, hidden, right)? Do you use any “exotic” plugins (sidebar or event) that might be related to the sidebars (sidebarhider comes to mind)? Do you have access to your web server's error logfile? Are all your plugins up to date?
About the only other way to debug this that I can think of is to disable (i.e. set to hidden) all sidebar plugins any try to activate only single ones, maybe starting with something simple like an HTML nugget. I guess it might be that you're using an exotic sidebar plugins that malfunctions with PHP7 and blocks the rest of them or something like that, but it's a long shot …