When navigating to the Health Check page, I received a blank page and the following error message in my Apache error log:
[Mon Oct 05 21:03:46.078760 2020] [php7:error] [pid 7233] [client 70.114.131.253:55029] PHP Fatal error: Uncaught Error: Call to undefined function curl_init() in /path/to/simplerisk/includes/healthcheck.php:599\nStack trace:\n#0 /path/to/simplerisk/includes/healthcheck.php(61): check_api_connectivity()\n#1 /path/to/simplerisk/admin/health_check.php(85): simplerisk_health_check()\n#2 {main}\n thrown in /path/to/simplerisk/includes/healthcheck.php on line 599, referer: https://demo.simplerisk.com/admin/health_check.php
This error message means that PHP is trying to use curl to perform a health check of the various services that SimpleRisk uses, but the PHP Curl library is not installed. To install it, run the following commands on your SimpleRisk instance as root:
Ubuntu:
sudo apt install php-curl
sudo service apache2 restart
RHEL/CentOS:
sudo yum install php-curl
sudo systemctl restart httpd
SUSE:
sudo zypper install php7-curl
sudo systemctl restart apache2