Blank Mail Page and Blank Settings

My Nextcloud instance (20.00) is in freenas. Accessed remotely with ssl termination at haproxy hosted on pfsense.

I am trying to get rainloop functional, because I found the mail app to be so slow that it was not usable and I am still using other email clients. No errors, no debugging issues either. So no real lead on why this was the case. And I am just not sure about the support on mail issues at this point.

Then I go to rainloop and the app is blank and the settings link directs to a blank page. I see history of opportunity around the app location and this is not new. I am not able to figure out if this has been resolved. If their is a work around. I really want to get Nextcloud to be my all in one solution, but the email issues have me using my time inefficiently trying to resolve email of all things. All other things work great. calendars, contacts files, blah blah blah. But email…nope. If anyone has any links or directions that I have missed in my searches I could really use a pointer …

FastCGI sent in stderr: “PHP message: PHP Fatal error: Uncaught Error: Class ‘OC’ not found in /data/nextcloud/apps/rainloop/app/index.php:8
Stack trace:
#0 /data/nextcloud/apps/rainloop/app/rainloop/v/1.14.0/include.php(57): __get_custom_data_full_path()
#1 /data/nextcloud/apps/rainloop/app/index.php(23): include(’/data/nextcloud…’)
#2 {main}
thrown in /data/nextcloud/apps/rainloop/app/index.php on line 8” while reading response header from upstream, client:***, server: ***, request: “GET /apps/rainloop/app/?admin HTTP/2.0”, upstream: “fastcgi://unix:/run/php-fpm/www.sock:”, host:
我尝试注释掉/data/nextcloud/apps/rainloop/app/index.php 的__get_custom_data_full_path方法,页面现在可以打开。但我不清楚原因。