I have experienced the same issue yesterday evening.
Disappointing but easy to fix…
– Download accesspress-parallax.1.23.4.zip >> https://wordpress.org/themes/download/accesspress-parallax.1.23.4.zip
– Unzip it on your computer.
– Connect to your server with FTP client (wp-content >> themes). Delete accesspress-parallax folder.
– Upload previous version (1.23.4).
– Your website is fixed !
For custom CSS stylesheet, use in dashboard >> Settings >> AccessPress Custom CSS
