Thank you for posting about this error message in the JS Console.
We will forward the issue to the Sales Engineering Team.
Which version of the Conditional Format Plug-in are you using?
Please note that the Conditional Format Plug-in has been archived on the Kintone Developer Program’s website and is now available as a Native Kintone Plug-in.
For questions regarding the official Conditional Format Plug-in, please get in touch with the Kintone Support Team.