> For the complete documentation index, see [llms.txt](https://docs.radicalframework.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.radicalframework.com/release-2/behaviors/textbox-behaviors/disableundomanager-.net-3.5-only.md).

# DisableUndoManager (.Net 3.5 only)