Adminlte: pieChart not work

[XxYyKk]

F12 console ：

jquery.min.js:2 jQuery.Deferred exception: Cannot read property 'getContext' of undefined TypeError: Cannot read property 'getContext' of undefined
at HTMLDocument.

Uncaught TypeError: Cannot read property 'getContext' of undefined
at HTMLDocument. (dashboard2.js:15)
at l (jquery.min.js:2)
at c (jquery.min.js:2)

please help!~

[almasaeed2010]

Looks like you removed the html canvas element that dashboard2.js is looking for. Please review the documentation of ChartJS v1 or v2 as needed to fix.

http://www.chartjs.org/docs/latest/

Thanks!