unknown error occured while running the code

Question

 hello i am facing 1 error and i don't know how to fix this error can you please help m the error is like,

(  Severity Code Description Project File Line Suppression State

Error 'ASP.heatrecoverywheel_aspx' does not implement interface member 'System.Web.IHttpHandler.IsReusable' c:\Users\admin\AppData\Local\Temp\Temporary ASP.NET Files\root\0c443de6\a910b9dc\App_Web_vkpx3g0n.4.cs 640)