One of our customer contacted us to fix the following issues on his WordPress Website.

• SSL not propperly showing on home page
• Template save is not working properly in WP-Admin > Appearance > Editor

SSL issue was due to the following Mixed Content error that we have fixed by deactivating Yeloni Exit Popup plugin

Mixed Content: The page at 'https://www.sitename.com/' was loaded over HTTPS, but requested an insecure image 'http://sitename.com/wp-content/plugins/yeloni-free-exit-popup/common/images/social-icons/round/facebook.png'. This content should also be served over HTTPS.
(index):1 Mixed Content: The page at 'https://www.sitename.com/' was loaded over HTTPS, but requested an insecure image 'http://sitename.com/wp-content/plugins/yeloni-free-exit-popup/common/images/social-icons/round/twitter.png'. This content should also be served over HTTPS.

When I check the template saving issue in WP-Admin > Appearance > Editor, I got the following error

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.

By doing a google search with the error message, I saw the suggestion to install and use the Health Check plugin

Before the installatiion, I created a backup using UpdraftPlus Backup/Restore

Then installed Health Check plugin and enabled the ‘Trouble Shooting Mode‘

I checked each plugin by clicking “Enable while troubleshooting”

When I checked with WordPress Social Login plugin, I got this error.

The loopback request to your site failed, this may prevent WP_Cron from working, along with theme and plugin editors.<br>Error encountered: (0) cURL error 28: Connection timed out after 10001 milliseconds

So I just deactivated the plugin and now I can edit/save the theme files without any issues.