Theme styles and scripts not printing
Those variables have been changed in beta16/RC1.

See HTML template head, scripts, styles and scripts_bottom replaced with placeholder_token:

Before

{{ head }}
{{ styles }}
{{ scripts }}
{{ scripts_bottom }}


After

&lt;head-placeholder token="{{ placeholder_token|raw }}"&gt;
&lt;css-placeholder token="{{ placeholder_token|raw }}"&gt;
&lt;js-placeholder token="{{ placeholder_token|raw }}"&gt;
&lt;js-bottom-placeholder token="{{ placeholder_token|raw }}"&gt;


The markup should be stable now with RC1, but when you're having trouble with a custom template, always compare it with the core default markup in the module providing it and/or the classy theme.