User was sent an email, when they clicked on the link to activate their account they got a blank page with the error 'This service is unavailable'.
Under the logs I see this error many times;

AbsoluteURL:/Default.aspx

DefaultDataProvider:DotNetNuke.Data.SqlDataProvider, DotNetNuke

ExceptionGUID:bd1bba8c-473e-4c63-81fa-9b94a71b58bc

AssemblyVersion:

PortalId:-1

UserId:-1

TabId:-1

RawUrl:

Referrer:

UserAgent:

ExceptionHash:OQ7DjarNupykChZcF6KKZJqwLdA=

Message:The Controls collection cannot be modified because the control contains code blocks (i.e. <% ... %>).

StackTrace:

InnerMessage:The Controls collection cannot be modified because the control contains code blocks (i.e. <% ... %>).

InnerStackTrace:

at System.Web.UI.ControlCollection.RemoveAt(Int32 index) at System.Web.UI.ControlCollection.Clear() at DotNetNuke.Modules.Admin.Authentication.DNN.Login. (EventArgs e) at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)

Source:

FileName:

FileLineNumber:0

FileColumnNumber:0

Please advise.