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