How to Fix Error “Load balancing failed to find a valid mailbox database”?
Summary: You might encounter an issue when enabling or creating a mailbox where it fails with the error, saying “Load balancing failed to find a valid mailbox database.” In this post, we will mention the possible solutions to fix this error. We will also mention an Exchange repair software that can help to easily recover mailboxes if the database doesn’t not mount.
In Exchange Sever, when enabling a mailbox which was disabled, we run the below cmdlet using the Exchange Management Shell (EMS).
Enable-Mailbox -Identity <email address> -Alias <alias>
For creating a new mailbox, we use the following command.
New-Mailbox -Name "<display name>" -UserPrincipalName <email address> -Password <password string or plain text> -Database <mailbox database> -FirstName <first name> -LastName <last name> -OrganizationalUnit <ad ou>
When these commands are executed, we may get the error saying “Load balancing failed to find a valid mailbox database”. If we try to enable or create a mailbox using the Exchange Admin Center (EAC), we may still get the same error.
Due to this, we can’t create or enable the mailbox. Let’s see how to fix the “Load balancing failed to find a valid mailbox database” error.
Troubleshooting the “Load Balancing failed to find a valid mailbox database” Error
Below we have mentioned some possible fixes to resolve the error.
Things to check before we start troubleshooting
Before we start troubleshooting and fixing the issue, there are some things we need to check. The first thing to check is the readiness of the command. Most of the time, we make a typo in the command when it comes to the user details or mailbox database. Since the error says that it failed to find a valid mailbox database, this could be the actual issue.
Before going further, we need to contain the issue. We need to check if this is occurring on a specific database or all the databases in our system. This helps to understand if the issue is with the database or the Exchange Server.
After checking that the details are correct if we still have the same issue, then we need to check if the mailbox database is really there and is mounted. This can be checked from the Exchange Admin Center (EAC).
After login, click on servers and then click on databases.
This can also be checked using the below PowerShell command in the Exchange Management Shell (EMS). It will show the Mounted state as True, if Exchange database is mounted.
Get-MailboxDatabase -Identity "<mailbox database>" | FL
The next thing is to check the overall status of our Exchange Server and there are no issues with our server. Ensure that all is up-to-date and any Exchange Server Cumulative Updates (CU) are installed.
Lastly, check if any changes have been done in the Active Directory schema or infrastructure. As Exchange Server is heavily dependent on the Active Directory, it is important that the schema and the setup are working fine. It’s best to retrace the changes to ensure that there was nothing that may have affected the Exchange Server.
Possible Fixes to Resolve the Error
In Exchange Server, we can set databases and lock them to not allow or exclude a particular database/s from provisioning of mailboxes. This can be set using the set-mailboxdatabase PowerShell command.
There is not only one parameter to fix the problem. We need to run the Get-MailboxDatabase PowerShell command as given below to identify if the database is locked or not.
Get-MailboxDatabase -Identity "<mailbox database>" | Format-List Name,IsExcludedFrom*,IsSuspended*
This will show the right information. If we run the Get-MailboxDatabase command on its own, it will show a lot of information, which is not relevant to this issue.
The solution, if the above is shown as True, is to change the settings to False. This can be done by using the Set-MailboxDatabase command as given below.
Set-MailboxDatabase "<mailbox database>" -<parameter> $false
After this is complete, we should re-run the Get-MailboxDatabase command to confirm that the parameters have been changed as desired.
If no one set this parameter, then why was it enabled?
Well, the reason is something might have happened to the Exchange Server, which might have triggered this. Usually, the most common factor is when the storage of the mailbox database is full and there is not enough space. When such thing happens, we can extend the storage
The above troubleshooting solutions will work, if everything was working fine. However, there might be situation where the mailbox database would not mount and show dirty shutdown state due to corrupted or missing transaction logs. To resolve the issue within minimal time and without using lot of resources, an Exchange database recovery software such as Stellar Repair for Exchange is the best alternative. With this application, you can easily browse through multiple databases and export granularly to PST and other file formats. You can also create a new mailbox database and export directly to a live Exchange Server database with automatic mailbox matching.