What should I be aware of when updating the IZYTRONIQ Enterprise?

Preparation: The first thing to do is to make sure that the Izytroniq service account is known and you have access to it. The account is the DB_Owner of the Izytron.Iq and SyncService databases. You can also find it out by checking which account in services.msc is running the Izytroniq.Backend.Syncservice service.

For the update the same installation files are used as for an installation. are used for the update. These can be downloaded here:

https://izytron.com/downloads.php

All packages should be run with the above user or as an alternative with a sysadmin of the SQL Server.

Izytroniq Enterprise requires Net Framework 4.8 to run.
Windows Server 2016 and 2019 will need to post-install the update:
https://support.microsoft.com/de-de/topic/microsoft-net-framework-4-8-offline-installer-f%C3%BCrwindows-9d23f658-3b97-68ab-d013-aa3c3e7495e0

Important: If you have Ultimate versions of Izytroniq Enterprise in use, they must have all their checked-out data checked back in at the time of the update. Otherwise, it may result in data loss or data compromise.
So no one should be out in the field with offline data while an update is being performed.
Once these requirements are met and the update is performed, the Izytroniq Backend SyncService service can be stopped.

1. Update the database
If the database is operated with a SQL user (instead of an AD or Windows user) the registry entries of the DB should be backed up before.
The path of these entries is:
HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\GossenMetrawatt\IZYTRON.IQ\BackEndDatabaseConnectionString
HKEY_LOCAL_MACHINE\SOFTWARE\GossenMetrawatt\IZYTRON.IQ\BackSyncServiceDatabaseConnectionString

If the application has not been changed since the installation (other SQL Server e.g.) the update of the database can be executed by double click, because the information was cached during the installation.

If this is not the case, the setup cache must be deleted:

In this case the Database.msi must be executed with the parameter BACKEND_SERVERNAME=(name of SQL instance)

2. Update of the Applications Server/SyncService
The certificate entry from the following config file can be saved:
C:\Program Files\Gossen-Metrawatt\IZYTRON.IQ
BackEnd SyncService\ IZYTRON.IQ.SyncSvc.exe.config

The string has the following format.
< serviceCertificate findValue="1234567890ABCDEF"
storeLocation="LocalMachine" storeName="My"
x509FindType="FindByThumbprint" />

Only this one string is saved, because the rest of the config files can change between versions.

The two packages are executed. After that, the certificate string saved above must be stored in the following files.

C:\inetpub\wwroot\IZYTRON.IQ\web.config

C:\Program Files\Gossen-Metrawatt\IZYTRON.IQ
BackEnd SyncService\ IZYTRON.IQ.SyncSvc.exe.config

Example of the final result from the web.config:

3. user permissions
Now in the IIS application pool izytroniq.Backendpool the user must be entered again:
Right click - Advanced Settings / advanced setting
Scroll down to Process Model
Edit Identity (Default ApplicatonPoolIdentity)

As well as in the Services.msc the user in the service are deposited again:

After that restart the service.
The users are lost because the exe files behind them are exchanged and Windows can't handle it.

4. Update LicensingTool
The update of the licensing tool is optional.

With the following checks you can test if the update was successful:

The service SyncService must not throw an error when started via Services.msc in the event viewer. Only the note that the service was started should be there.
The SQL query
select value from database_info
returns the new version.

The test pages can be called without errors. These are:
https://servername/syncservice
https://servername/bits
https://servername/izytron.iq/handshakeremoteservice.svc

When all tests are passed the Izytroniq Enterprise should be running again and you can now start the automatic client update by starting the client applications.

Troubleshooting:
When overwriting older versions of the application server it can happen that the application pool disappears. In this case, simply uninstall the ApplicationSercer package completely and reinstall it. At least the four entries from the screenshot above must be visible.

The same applies to the entry BackSyncSericeDatabaseConnectionString in the registry. If this was not created, uninstall and reinstall the SyncService package.
In this case the SQL Server must also be added to the registry:

HKEY_LOCAL_MACHINE\SOFTWARE\GossenMetrawatt\IZYTRON.IQ\BackSyncServiceDatabaseConnectionString

Data Source=SQLSERVER;Initial Catalog=SyncService;Integrated
Security=True;MultipleActiveResultSets=True

Sometimes when performing the update of ApplicationServer or SyncService, the following message may appear:

The reason for this is often that the permissions with which the Izytroniq was first installed can no longer be traced by Windows.
In this case cancel, then completely uninstall the corresponding package and then reinstall it.

In this case, the user is not authorized to access SQL Server.
Here the registry entries must be restored (see point 1).