WebForms UnobtrusiveValidationMode 需要“jquery”ScriptResourceMapping。请添加一个名为 jquery (区分大小写)的 ScriptRes

在webconfig中找到
        <appSettings>
        <add key=" aspnet:UseTaskFriendlySynchronizationContext" value="true" />
         <add key="ValidationSettings:UnobtrusiveValidationMode" value="WebForms" />
         </appSettings>

         删除<add key="ValidationSettings:UnobtrusiveValidationMode" value="WebForms" />即可。

 

        如果没有上面两句的话：在配置中中添加

      <appSettings>
      <add key="ValidationSettings:UnobtrusiveValidationMode" value="None" />
      </appSettings>

然后刷新页面oK成功