Exchange Online - Data returned by the remote Get-FormatData command is not in the expected format

Historical remote PowerShell issue

Updated 23 October 2026: This article records a 2020 Exchange Online remote-session formatting error. The SerializationLevel=Full connection-URI workaround below is retained as historical context, not a current troubleshooting instruction. Start with a supported ExchangeOnlineManagement module and Microsoft’s current connection guide.

For an interactive connection using the current module’s modern authentication flow, the documented pattern is:

# Replace with your administrator account; follow the authentication prompt.
Connect-ExchangeOnline -UserPrincipalName 'admin@contoso.onmicrosoft.com'

For unattended jobs, use app-only certificate authentication or a supported managed identity. Do not add a legacy endpoint URI to a current deployment solely because an error message resembles the historical report.

Original symptom and workaround

The original workflow failed while opening a remote session with:

Data returned by the remote Get-FormatData command is not in the expected format.

At the time, a reported workaround added SerializationLevel=Full to the old endpoint. Shown as text rather than an executable recommendation:

Historical only:
Connect-ExchangeOnline -ConnectionUri "https://outlook.office365.com/powershell-liveid?SerializationLevel=Full"

The original report did not establish a universal root cause. Its feedback form and performance claim have been removed because they do not provide a current diagnostic path. Record the module version, host environment and full error when investigating a current connection failure, then follow the current documentation for that environment.