This can happen if you copy and paste template files without properly modifying all of the jet declaration.

如果您只是拷贝并粘贴模板文件，而没有正确地修改所有的 jet 声明，那就可能出现这种情况。

youdao

She decided that with the buzz on Twitter, she could start organizing a group of fellow all-you-can-jet travelers, calling it the 599club.

CNN: Some travelers push the envelope on all-you-can-jet deal