ASP.Net Form authentication mode does not work

please help with the following:

I have a web project that has form authentication, it works as long as it does not have access to the logi, but when it arrives at the login, the IIS error shows access denied to the login:

<authentication mode="Forms">
  <forms name="FormsAuthDB" defaultUrl="Default.aspx" loginUrl="~/Login.aspx" protection="All" timeout="10" path="/">
  </forms>
</authentication>
<authorization>
  <deny users="?" />
</authorization>