The File Manager HTML editor break iFrame.

Symptoms

If you use the HTML editor from the File Manager the iFrames does not work

Description

The HTML editor from File Manager breaks the iFrame by adding sandbox attribute to iFrame

We've opened an internal case for our development team to investigate this further. For reference, the case number is CPANEL-47716. Follow this article to receive an email notification when a solution is published in the product. 

Workaround

• Click the source in the HTML Editor
• Search for the affected iframe and remove the sandbox attribute
• Save the file

Alternatively, use the text editor option in the file manager or use a local editor and upload the file