When I click on "Customize" for the newspaper theme I get an error:

Hello,

Usually, this error appears when the requirements aren’t set like in our guide, please make sure you have added the limit also in your wp-config.php file, in config is WP_MEMORY_LIMIT not PHP Memory Limit (there is a typo, sorry) – https://forum.tagdiv.com/requirements-for-newspaper/
please increase all lower requirements and follow all steps; make sure that the theme is activated and use an SSL plugin for HTTPS.

Hope this helps you!

Thank you!