Exchange Online PowerShell Error: “Cannot process argument transformation on parameter ‘Identity’. Cannot convert value “” to type “Microsoft.Exchange.Configuration.Tasks.RecipientIdParameter””

Question

We recently upgraded a client’s personal Office 365 account to a Microsoft 365 Business plan and added their custom domain to set up Exchange Online. Everything seems configured correctly in the Exchange Admin Center, and we’ve verified that all necessary rights and permissions are assigned there.

However, when trying to add or modify mailbox permissions (e.g., using cmdlets like Add-MailboxPermission) in PowerShell for the business setup, we encounter this error:

“Cannot process argument transformation on parameter ‘Identity’. Cannot convert value “” to type “Microsoft.Exchange.Configuration.Tasks.RecipientIdParameter”. Error: “Parameter values of type Microsoft.Exchange.Configuration.Tasks.RecipientIdParameter can’t be empty””

Answer 1

Hi Williams B

Thanks for reaching out to Microsoft Q&A forum support

As far as I know, this error occurs because the -Identity parameter is either empty or not receiving a valid mailbox identifier. The Identity parameter is mandatory and expects a string that specifies the mailbox (such as an email address, alias, or distinguished name). When given an empty string or an uninitialized variable, the cmdlet cannot convert this value to the expected RecipientIdParameter type, resulting in the error shown.

That said, in order to resolve this error, ensure that the -Identity parameter is explicitly provided with a valid mailbox identifier string, and avoid passing empty or null values. For example, if running this command in a script or loop, verify that the variable holding the mailbox identity contains a valid string before invoking Add-MailboxPermission

For example:

Add-MailboxPermission -Identity "******@yourdomain.com" -User "******@yourdomain.com" -AccessRights FullAccess

By ensuring the -Identity parameter is never empty and always receives the correct mailbox identifier string, the cmdlet should run successfully without the parameter transformation error.

Link reference: https://learn.microsoft.com/en-us/exchange/recipients-in-exchange-online/manage-permissions-for-recipients

Hope my answer will help you

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