The following exception may be seen in the Office 365 module log file:
2019-07-10 17:34:37Z| 8080| 18|FATAL| ApplicationUnhandledException|Unhandled exception: IsTerminating: True Void Office365Checker(System.Collections.Generic.List`1[System.Net.NetworkCredential], ArchiveShuttle.Modules.Common.ModuleClient, System.Guid)Object reference not set to an instance of an object.
at ArchiveShuttle.Module.Office365.Program.Office365Checker(List`1 networkCredentials, ModuleClient moduleClient, Guid moduleId)
at ArchiveShuttle.Module.Office365.Program.CheckO365Credentials(ModuleClient moduleClient, Guid moduleId)
at ArchiveShuttle.Module.Office365.Program._1()
at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Threading.ThreadHelper.ThreadStart()
This is most likely due to a configuration issue around the customers firewall. When the module makes a connection to Office 365, and the connection is forcibly closed we do not detect that situation, and attempt to read data from the connection afterwards which results in the error.
After confirming with the customer that their firewall is configured to allow connections using basic authentication to the Office 365 PowerShell endpoint, try checking the credentials in the Credentials Editor. Once the Credentials Editor test passes, restart the Office 365 module and review the module log file.