Problem with admin panel. See this, when I'm trying to enter it.
Fatal error: Uncaught Error: Call to a member function setActive() on boolean in .../magento/vendor/magento/module-backend/Model/View/Result/Page.php on line 60
Have no idea, why that stuff had happened. I have cleaned the cache (from terminal), in git checkouted on the working revision before this stuff, upgraded modules and re-compile the project. Id hasn't helped.
Would be glad to hear any suggestions.
P.S. I was learning, how to override and extend core layouts (did NOT touched them).