PHP update breaks latest WP

What is the admin email address for the site? Do you have access to that email account?

What is the admin email address for the site

please do not ask for email, treat this question as “do you remember your admin email? yes or no”

If you havent received anything from your site, then consider looking at PHP error log, end of file, strings with “Fatal”

The admin email address is my email that I use every day and yet I haven’t received any emails and I checked my spam folder.

I did check the Raw Access Logs in my cPanel and I don’t see anything with the word “fatal” and the last two lines are:

196.52.2.39 - - [05/Apr/2020:13:25:45 -0400] "GET /blog/wp-admin/index.php HTTP/1.1" 200 31384 "https://www.xxx.com/blog/wp-admin/users.php" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.149 Safari/537.36"

196.52.2.39 - - [05/Apr/2020:13:25:47 -0400] "GET /blog/wp-admin/admin.php?page=stats&noheader&dashboard&width=1184 HTTP/1.1" 200 1636 "https://www.xxx.com/blog/wp-admin/index.php" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.149 Safari/537.36"

^^ this is Apache access.log,
You should look at error.log, it can be common with Apache or separate log file for PHP, you need to look for PHP error log

where can I find the PHP error log… in cPanel the only log I see is the Raw Access Log and in FTP I don’t see an error_log file

You can try to ask your webhosting support

Unless the PHP error_log has been defined to be in a specific place, then it will place the error_log file in the same directory as the PHP script that generated it. So, look in both the /blog/ and /blog/wp-admin/ directories for it.

My host said to turn on display_errors and when I did that I see this:

Fatal error: Uncaught Error: Call to undefined function WebSharks\CometCache\mb_strtolower() in /home/marcurse/public_html/blog/wp-content/plugins/comet-cache/src/includes/stub.php:20 Stack trace: #0 /home/marcurse/public_html/blog/wp-content/advanced-cache.php(39): include_once() #1 /home/marcurse/public_html/blog/wp-settings.php(97): include('/home/marcurse/...') #2 /home/marcurse/public_html/blog/wp-config.php(23): require_once('/home/marcurse/...') #3 /home/marcurse/public_html/blog/wp-load.php(37): require_once('/home/marcurse/...') #4 /home/marcurse/public_html/blog/wp-admin/admin.php(34): require_once('/home/marcurse/...') #5 /home/marcurse/public_html/blog/wp-admin/index.php(10): require_once('/home/marcurse/...') #6 {main} thrown in /home/marcurse/public_html/blog/wp-content/plugins/comet-cache/src/includes/stub.php on line 20

so I assumed the problem was being created by the CometCache plugin so I deactivated it and then even deleted it but even after deleting it I still get the error “There has been a critical error on your website. Please check your site admin email inbox for instructions.” even though dispaly_errors is on (it doesn’t show another error)

This time I did get the email with the recovery mode link and the email said the plugin that doesn’t work is Facebook. This is strange since it’s the official Facebook plugin for WP:

Version 1.5.5 | By Facebook | Visit plugin site
 This plugin failed to load properly and is paused during recovery mode.

An error of type E_COMPILE_ERROR was caused in line 84 of the file /home/marcurse/public_html/blog/wp-content/plugins/facebook/social-plugins/widgets/like-box.php. Error message: 'break' not in the 'loop' or 'switch' context