Mentioned in https://github.com/backdrop/backdrop-issues/issues/2527#issuecomment-279...
Running cron.php from the browser will show a blank page if it is successful. This can be confusing for beginners, so perhaps it could output a simple message like "Scheduled tasks run successfully."
GitHub Issue #:
2535
Recent comments
The Mail System and MimeMail modules are now installed. I'll let you know if they solve the problem. Thank you Herb
HTML Email treated as plain text
If you haven't already I recommend installing Mail System and MimeMail. The latter will help format emails as HTML and first helps with configuring which module will handle the formatting...
HTML Email treated as plain text
The horrors of cut/paste! Brilliant, thanks.
SQLSTATE[22007]: Invalid datetime format: 1366 Incorrect string value: