Topshelf Windows Service times out Error 7000 7009 - vb.net

Question

I have a windows service programmed in vb.NET, using Topshelf as Service Host.
Once in a while the service doesn't start. On the event log, the SCM writes errors 7000 and 7009 (service did not respond in a timely fashion). I know this is a common issue, but I (think) I have tried everything with no result.
The service only relies in WMI, and has no time-consuming operations.
I read this question (Error 1053: the service did not respond to the start or control request in a timely fashion), but none of the answers worked for me.
I Tried:
Set topshelf's start timeout.
Request additional time in the first line of "OnStart" method.
Set a periodic timer wich request additional time to the SCM.
Remove TopShelf and make the service with the Visual Studio Service Template.
Move the initialization code and "OnStart" code to a new thread to return inmediately.
Build in RELEASE mode.
Set GeneratePublisherEvidence = false in the app.config file (per application).
Unchecked "Check for publisher’s certificate revocation" in the internet settings (per machine).
Deleted all Alternate Streams (in case some dll was marked as web and blocked).
Removed any "Debug code"
Increased Window's general service timeout to 120000ms.
Also:
The service doesn't try to communicate with the user's desktop in any way.
The UAC is disabled.
The Service Runs on LOCAL SYSTEM ACCOUNT.
I believe that the code of the service itself is not the problem because:
It has been on production for over two years.
Usually the service starts fine.
There is no exception logged in the Event Log.
The "On Error" options for the service dosn't get called (since the service doesn't actually fails, just doesn't respond to the SCM)
I've commented out almost everything on it, pursuing this error! ;-)
Any help is welcome since i'm completely out of ideas, and i've been strugling with this for over 15 days...

Answer 1

For me the 7009 error was produced by my NET core app because I was using this construct:
var builder = new ConfigurationBuilder()
.SetBasePath(Directory.GetCurrentDirectory())
.AddJsonFile("appsettings.json");
and appsettings.json file obviously couldn't be found in C:\WINDOWS\system32.. anyway, changing it to Path.Combine(AppContext.BaseDirectory, "appsettings.json") solved the issue.
More general help - for Topshelf you can add custom exception handling where I finally found some meaningfull error info, unlike event viewer:
HostFactory.Run(x => {
...
x.OnException(e =>
{
using (var fs = new StreamWriter(#"C:\log.txt"))
{
fs.WriteLine(e.ToString());
}
});
});

Answer 2

I've hit the 7000 and 7009 issue, which fails straight away (even though the error message says A timeout was reached (30000 milliseconds)) because of misconfiguration between TopShelf and what the service gets installed as.
The bottom line - what you pass in HostConfigurator.SetServiceName(name) needs to match exactly the SERVICE_NAME of the Windows service which gets installed.
If they don't match it'll fail straight away and you get the two event log messages.

Answer 3

I had this start happening to a service after Windows Creator's Edition update installed. Basically it made the whole computer slower, which is what I think triggered the problem. Even one of the Windows services had a timeout issue.
What I learned online is that the constructor for the service needs to be fast, but OnStart has more leeway with the SCM. My service had a C# wrapper and it included an InitializeComponent() that was called in the constructor. I moved that call to OnStart and the problem went away.