Upgrading from 8.6.10 to 8.6.11 and 8.6.12 causes the white screen of death to appear on specific admin pages.
"/admin/modules/update" and "/admin/modules/install" both work, but "/admin/modules/uninstall" gives the error:
Twig\Error\SyntaxError: An exception has been thrown during the compilation of a template ("Attribute "name" does not exist for Node "Twig\Node\CheckToStringNode".") in "core/themes/stable
"/admin/reports/dblog" gives:
Twig\Error\SyntaxError: An exception has been thrown during the compilation of a template ("Attribute "name" does not exist for Node "Twig\Node\CheckToStringNode".") in "core/themes/classy
"/admin/reports/updates" gives:
Twig\Error\SyntaxError: An exception has been thrown during the compilation of a template("Attribute "name" does not exist for Node "Twig\Node\CheckToStringNode".") in "core/themes/stable
There may be more, but that's all I've come across so far.