Refused to Apply Style because its MIME type (text/html) is not a supported stylesheet MIME type, and strict MIME checking is enabled.

This error means that something went wrong — somewhere — while OMGF’s API was instructed to generate a stylesheet. Due to the way WordPress’ was built, this could literally mean that any plugin at any point in time, before or after OMGF’s API was invoked, caused either an error, warning or notice.

First, open your
wp-config.php file and make sure any of the following constants are set to false, or not set at all:

–
WP_DEBUG
–
WP_DEBUG_LOG
–
WP_DEBUG_DISPLAY
–
SCRIPT_DEBUG

If any of these constants are set (e.g.
define('WP_DEBUG', true);) either remove the line or change true to false. This will stop WordPress from attempting to print any notices or warnings in text/html, effectively allowing OMGF to print its stylesheet in text/css again.