I recently upgraded from version 7 to version 15.1.2 (NuGet) of the AjaxControlToolkit. I've noted several issues with the HtmlEditor: (all issues tested on the latest stable Chrome release.)
1) Required CSS references aren't present when inheriting the control into a custom class, e.g., public class MyEditor : AjaxControlToolkit.HtmlEditor.Editor { ... } is missing most styling when used on a page. Changing the class to inherit Control and adding an Editor to this.Controls programatically works as expected.
2) The "Insert Link" popup is missing all text, and doesn't actually insert a link into the content window after use.
3) The paste button throws a JavaScript error: "Uncaught Sys.ArgumentUndefinedException: Sys.ArgumentUndefinedException: Value cannot be undefined.
Parameter name: format" (paste from Word might have a similar issue, I'm not entirely sure.)
All other default toolbar buttons seem to work correctly.
1) Required CSS references aren't present when inheriting the control into a custom class, e.g., public class MyEditor : AjaxControlToolkit.HtmlEditor.Editor { ... } is missing most styling when used on a page. Changing the class to inherit Control and adding an Editor to this.Controls programatically works as expected.
2) The "Insert Link" popup is missing all text, and doesn't actually insert a link into the content window after use.
3) The paste button throws a JavaScript error: "Uncaught Sys.ArgumentUndefinedException: Sys.ArgumentUndefinedException: Value cannot be undefined.
Parameter name: format" (paste from Word might have a similar issue, I'm not entirely sure.)
All other default toolbar buttons seem to work correctly.