Glenn

Trying to fix it by"npm install dayjs --save". if it does not work, I will install the old version to get rid of this matter.

Solution 1 works, but you need to add: "homepage": "https://myusername.github.io/my-app)" in the package.json, and add the export PUBLIC_URL="/kendo-demo" in the terminal. once you add two sections, then you can deploy...

Yes, if the developer can fix this bug or give a solution, would be appreciated a a lot.