You will notice a redirection that may fail, to verify run the following Remote PowerShell cmdlets to Office 365:
$cred = Get-Credential
$Session = New-PSSession -ConfigurationName Microsoft.Exchange -ConnectionUri https://ps.outlook.com/powershell -Credential $cred -Authentication Basic -AllowRedirection
Import-PSSession $Session
Notice the Redirection. MessageStats will try to connect to outlook.office365.com instead of ps.outlook.com.
Installation Instructions:
1. Make sure no MSOnline RP tasks running
2. Logon to the MessagStats server where the Report Pack is installed and navigate to <MessageStats>\Report Packs\Microsoft Online
3. Backup the existing QmsBposWcfServer.exe and replace with the one in QmsBposWcfServer_7.4.1.101.zip
4. Create the Gathering Credential again and run your task.