Who is this training for:
If you have updated your WordPress site to the latest version 4.8.1. You may have noticed a new "Custom HTML" widget and that some of your Text Widgets are now showing an error message like the one below.
This widget may contain code that may work better in the new “Custom HTML” widget. How about trying that widget instead?
Log into your WordPress site and go to your widgets area by clicking Widgets under Appearance
Click the drop down arrow on the text widget to see if you have the error message
If you do, then you need to drag and drop a custom html widget under each text widget that has the error message.