Missing Widget

Thank you for the great plugin. I am using this TOC plugin with SiteOrigin page builder and I am getting the following error lately and the TOC not working anymore.

Missing Widget! The widget luckywptableOfContentspluginWpWidget is not available.

Here are the screenshots

https://drive.google.com/file/d/1zrvMLXtmm1gUvN6o6hHINL9_B8oLb-rh/view?usp=sharing

https://drive.google.com/file/d/11xcb2-VGwlS-eMlYaRcne2scHmwDFROu/view?usp=sharing

Please let me know if you need further info.