Websites will run into problems. Whether you're using Drupal or any other software, there will be problems at some point.
Drupal runs on PHP and when PHP has problems, it reports them to you.
However, often these errors will appear on your site and will be visible to visitors, as in the image below:
In this tutorial, we're going to give you a quick introduction to these errors. We'll explain the different types that might appear on your site and how you can stop them from showing.
There are three main ways in which PHP will report problems: notices, warnings and errors.
What are PHP Notices?
These are the least important. According to the official PHP website, notices are generated when:
"the script encountered something that could indicate an error, but could also happen in the normal course of running a script."
What are PHP Warnings?
Warnings are more serious, but probably won't break your site. According to the official PHP website, warnings are:
"non-fatal errors. Execution of the script is not halted."
What are PHP Errors?>
Errors are the most serious type of problem and may break your site. According to the official PHP website, warnings are:
"Fatal run-time errors. These indicate errors that can not be recovered from, such as a memory allocation problem. Execution of the script is halted."
Solution #1: Disable Error Reporting on Your Drupal Site
One solution is to simply stop the errors from showing.
- Go to Configuration > Logging and Errors.
- You have three choices:
- None will disable all error reporting.
- Errors and warnings will display on the most serious problems.
- All messages will display all problems and is probably only useful for developers.
Solution #2: Fix the Problem
Yes, yes, I know this is a controversial idea. Fixing a problem is definitely harder than hiding a problem.
Here are some suggestions to help you fix the problem. Please backup your site before trying any of these.
- Make sure your Drupal site and all your modules and themes are up-to-date.
- Search Google and Drupal.org for anyone who has reported the same message. See if they have found a solution.
- Read the message itself for hints about the problem. For example, the problem in the image at the top of this tutorial is all/modules/calendar/includes/calendar_plugin_display_page.inc on line 47. This tells that the problem may well be with the Calendar module, because the error is coming from the Calendar module folder. If the problem is serious, you might consider disabling the problematic module or theme.