Hi there
So I’ve done the following
1 - all up to date, plugins and Wordpress
2 - cleared the cache
3 - deactivated all plugins
4 - Removed all CSS (I am seeing this message when I go to the theme/editor - Unable to communicate back with site to check for fatal errors, so the PHP change was reverted. You will need to upload your PHP file change by some other means, such as by using SFTP.)
5 - Remained .htacess to .htaccess-bak and hit save on permalinks
6 - Running PHP v7.0.31
7 - PHP Max Execution Time increased from 30s to 300s
8 - PHP Memory limit increase to 512
I sent my details via private note.
Thanks
James