Summary: Installation of the Cumulative Updates (CU) is important to ensure security and compatibility of the Exchange Server. Sometimes, while installing the updates, you may encounter an error, such as Exchange Server update error 5506. In this post, we will discuss the error 5506 and the solutions to fix it. We’ll also mention an Exchange repair software that can help in restoring data from damaged or corrupt database to a new live Exchange database.
A user has reported encountering an error when upgrading the Exchange Server 2019 to the Cumulative Update (CU). During the installation, the setup failed, showing the below error message:
The following error was generated when "$error.Clear();
Install-ExchangeCertificate -services IIS -DomainController $RoleDomainController
if ($RoleIsDatacenter -ne $true -And $RoleIsPartnerHosted -ne $true)
{ Install-AuthCertificate -DomainController $RoleDomainController } " was run: "Microsoft.Exchange.Management.Clients.FormsAuthenticationMarkPathUnknownSetError: An unexpected error occurred while modifying the forms authentication settings for path /LM/W3SVC/1. The error returned was 5506. at Microsoft.Exchange.Configuration.Tasks.Task.ThrowError(Exception exception, ErrorCategory errorCategory, Object target, String helpUrl) at Microsoft.Exchange.Configuration.Tasks.Task.WriteError(Exception exception, ErrorCategory category, Object target) at Microsoft.Exchange.Management.SystemConfigurationTasks.InstallExchangeCertificate.EnableForServices(X509Certificate2 cert, AllowedServices services) at Microsoft.Exchange.Management.SystemConfigurationTasks.InstallExchangeCertificate.InternalProcessRecord() at Microsoft.Exchange.Configuration.Tasks.Task.<ProcessRecord>b__91_1() at Microsoft.Exchange.Configuration.Tasks.Task.InvokeRetryableFunc(String funcName, Action func, Boolean terminatePipelineIfFailed)".
Due to this error, the installation gets failed, leaving the Exchange Server unusable with services unable to start and a bunch of issues in the Event Viewer.
Below, we’ll be discussing the possible solutions to fix this error and to bring back the services in minimum time.
Solutions to Fix Exchange Server 2019 Error 5506
Though you can re-run the update, it will surely fail and you may end up getting your Exchange in an even worst situation. If your only Exchange Server becomes accessible, then you need to restore the services as soon as possible with minimum impact.
From the error message, it looks that the issue is related to the certificates. There is a possibility that the CU installation failed due to an expired certificate. Therefore, the first thing to do is check the certificates and ensure that they are not expired. For best practice, it’s suggested to never allow the certificates and renew them beforehand.
Next, you can check the IIS and the default Web Site HTTPS bindings. You can try to replace the one from the certificate authority with the self-signed certificate provided by default during the installation. Here is how to do so:
- Open the Internet Information Services Manager.
- Expand the Server and expand Sites.
- Click on Default Web Site.
- Click on Bindings in the right pane.
Find the entries with the Type set as https.
- Highlight them and click on Edit.
- Replace the SSL Certificate with the default self-signed certificate.
Once this is done on all https entries, restart the IIS. For this, open the command prompt as Administrator and run the below command.
Now, you can restart the installation of the Exchange Server Cumulative Update (CU). In most cases, this would work.
After the installation is complete and to ensure that the web services are secured with a certificate authority, you can replace the self-signed certificate with the one from the certificate authority.
What if the above solution doesn’t work?
It may happen that the re-run of the installation does not work. In addition, the corrupt installation may lead to missing or corrupted transaction logs, or even with a damaged database. In such a case, you would end up with an unusable Exchange Server. In this scenario, the only solution is to recreate the Exchange Server virtual machine or server and import the data into the new server. However, you cannot just de-attach a database and attach it to another server. There is a whole process to re-install the server. Also, importing the data into the server would be a hard task.
However, you can take the help of a Exchange Server Recovery software, such as Stellar Repair for Exchange to restore the data from the damaged/corrupt database. With this software, you can open the database of any version of Exchange Server, with no size limit. You can browse through the database and export granularly to PST and other file formats.
In such a situation as this, you can simply export the data from the database directly to a live Exchange Server database. You can not only export user mailboxes but also archives, shared mailboxes, disabled mailboxes, and public folders.
