After having months of bot serving registrations on one of my sites currently on 7.3.1 and having fixed the bot registration from default to host-specific, I have numerous deleted users.  Here lies the issue- The Remove Deleted Users button on the User Accounts module doesn't remove anyone! (Host log-in)  

Neither does Remove Unauthorized Users - 

Why?  how to correct the condition? 

I seem to have lost the event viewer module somewhere in an upgrade- I found the log viewer - which says there was an exeption  points to Portal 1 :

AssemblyVersion 7.3.1 PortalID -1 PortalName UserID -1 UserName ActiveTabI 

Not sure where to go on this?

I have numerous exception errors...

AssemblyVersion:7.3.1

PortalID:-1

PortalName:

UserID:-1

UserName:

ActiveTabID:-1

ActiveTabName:

RawURL:

AbsoluteURL:

AbsoluteURLReferrer:

UserAgent:

DefaultDataProvider:DotNetNuke.Data.SqlDataProvider, DotNetNuke

ExceptionGUID:723f940e-d479-4550-a8d0-7bbb324503af

InnerException:Sequence contains more than one matching element

FileName:

FileLineNumber:0

FileColumnNumber:0

Method:System.Linq.Enumerable.Single

StackTrace:

Message:

System.InvalidOperationException: Sequence contains more than one matching element
   at System.Linq.Enumerable.Single[TSource](IEnumerable`1 source, Func`2 predicate)
   at DotNetNuke.Services.Scheduling.Scheduler.CoreScheduler.GetServer(String executingServer)
   at DotNetNuke.Services.Scheduling.Scheduler.CoreScheduler.LoadQueueFromTimer()
   at DotNetNuke.Services.Scheduling.Scheduler.CoreScheduler.Start()

Source:

Server Name: rose