With the Jakarta release, the TinyMCE editor has seen some improvements and new features added, see User interface (UI) release notes - Jakarta
One of the added features was Paste Formatting Options described in our documentation: Paste content into the HTML editor
Due to this new feature, when users paste content into any html field, they see a popup with a message asking whether to keep or remove the formatting in the pasted content.
For users who do a lot of "copy and paste" operations in the html field as part of their daily job, this new functionality might be annoying. This article details how to disable this new feature with TinyMCE editor.
Import the attached sys_ui_macro_546aeeafdbcbc70081e390b6db961908.xml on your instance.
Please refer to the document below for instructions on how to import an XML file into an instance: Import an XML file
Importing this record will add a UI macro named tinymce_setup to your instance. Make this UI macro active. Once the UI Macro is activated save it and clear the cache (perform a stats.do), it provides the ability to override the default tinymce_setup.xml.
The following properties are added in the attached UI Macro, so that the Paste Formatting option is disabled, and the content will always be pasted without any formatting. If there were any formatting, they will be cleaned.
This UI macro overrides code released in JP7, KP1, and London. It is not recommended to apply this fix to versions older than Jakarta without further investigation. If applying this update to releases later than London, it may override bug fixes or improvements made in that release.
Ref. additional TinyMCE properties: https://www.tinymce.com/docs/plugins/powerpaste/
Ref. enhancement request discussion on ServiceNow Community: https://community.servicenow.com/message/1250203#1250203