Troubleshooting Exchange Online EXOv3 – Module Could Not Be Correctly Formed

10 min

Issue

When connecting to Exchange Online using the Exchange Online PowerShell V3 (EXOv3) module with app-only authentication, the following error may occur:

Module could not be correctly formed. Please run Connect-ExchangeOnline again.

This can occur when the Azure App Registration has been configured with the incorrect Exchange Online API permission.

Cause

The App Registration is configured with the following API permission:

Exchange.ManageAsAppV2

This permission is incorrect for this configuration and prevents EXOv3 from successfully establishing the Exchange Online connection.

Resolution

Update the API permissions assigned to the App Registration.

1. Remove the incorrect API permission

Remove:

Exchange.ManageAsAppV2

2. Add the correct API permission

Add:

Exchange.ManageAsApp

Ensure the required admin consent has been granted after changing the API permission.

Incorrect API Permission

Exchange.ManageAsAppV2

Screenshot: Incorrect API permission configuration

Correct API Permission

Exchange.ManageAsApp

Screenshot: Correct API permission configuration

Error Example

When the incorrect permission is configured, running Connect-ExchangeOnline may return an error similar to:

PS> Connect-ExchangeOnline -AppId [REDACTED] -Organization '[REDACTED].onmicrosoft.com' -CertificateThumbPrint [REDACTED] Module could not be correctly formed. Please run Connect-ExchangeOnline again. At C:\Program Files\WindowsPowerShell\Modules\ExchangeOnlineManagement\3.6.0\netFramework\ExchangeOnlineManagement.psm1:766 char:21 + throw $_.Exception; + ~~~~~~~~~~~~~~~~~~~ + CategoryInfo : NotSpecified: (:) [], ParentContainsErrorRecordException + FullyQualifiedErrorId : RuntimeException

Verification

After updating the App Registration to use Exchange.ManageAsApp and granting admin consent, run the connection command again:

Connect-ExchangeOnline -AppId [APP-ID] -Organization '[TENANT].onmicrosoft.com' -CertificateThumbPrint [CERTIFICATE-THUMBPRINT]

The Exchange Online connection should now complete without the Module could not be correctly formed error.