Runtime error and parse error in web.config after hosting a Asp.net website

i have hosted my Asp.net website at somee.com . After hosting only the login.aspx is opening after login (Authentication) the page redirected to dashboard.aspx. in between this i got Runtime error saying as image mentioned .Runtime Error Image

after that adding in web.config file as instructed in Runtime error i got another error that is parse error as shown in image here.Parse Error after adding customErrors mode="Off" in web.config file

how can i solve this issue .