After Click on Add new Button  Let's Configure Line chart all Required Field. 

Click on Save Button

Click on Add Dashboard Detail Respective your  LIne Chart Dashboard . Click On Add New Button.

After configure Dashboard Please Create Tree link for your Dashboard. 

Go to Tree X-Admin Module Configure Tree For Your Gauge Chart Other Wise Backoffice Database Side You can configure Tree  

Node URL: REDIRECT#Dashboard/NewDashboard.aspx?name=GaugeChart

Click on Scree Menu Click ON your chart

Here is no data available in Our Database So wee can't show Line chart