On about Sept 1st we were informed by google search console that we had 60 server 500 errors in the /wp-includes directory. After disabling on the plugins, checking for the same errors on other domains and then after starting a fresh brand new server with a new wordpress install, we have been getting the same server errors. The only common thread is the generate press theme. it seems we are missing these functions when enabling generate press as the theme:
Class ‘Text_Diff_Renderer’
Class ‘SimplePie_Sanitize’
Class ‘WP_Session_Tokens’
Class ‘Walker’
Class ‘Text_Diff_Renderer_inline’
Class ‘WP_HTTP_Response’
Class ‘IXR_Server’
Class ‘WP_Image_Editor’
Class ‘SimplePie_File’
Class ‘WP_Dependencies’
Class ‘SimplePie_Cache’
Class ‘Requests_Hooks’
Class ‘WP_Image_Editor’
Class ‘WP_Dependencies’