Jet Brains in not detecting ASP keyword

HI,

While building the  ASP.net project in Jet Brains Rider getting the below error , looks like the the ASP keyword is not recognized. Please see the below highlight line of code (line no 25) where I am getting this error.

Please refer the other attachment for the list of error getting when I am building the project...

Kindly let me know to support this ASP keyword  do we need refer any of the base class library?

for your information, the same project I am able to build successfully in the Visual studio IDE

Thanks & Regards,

Anand Krishna.