Introduction

This is a short blog post that I decided to include as I did not find any result while I was troubleshooting it and maybe it gets picked up by search engines and can be useful for others.

The Error

I was called by a customer who was struggling to move in the Use network upload to import your organization’s PST files to Microsoft 365, they were receiving an “Unknown” error after the step 6 (Start the PST import job), they also said that they checked everything, pst file corruption, if the pst file was protected by a password, mostly all customer’s investigation was focused on the pst file itself.

The solution

I asked to see the mapping csv file used for the network upload, even though the wizard said it was succesfully validated.

Turns out, that the csv file had a typo in the FALSE/TRUE field, once I asked to correct it, they could pass the step 6 and succesfully import the pst file into a mailbox.

Lesson learned by the customer, don’t always trust what the UI or the process is telling you when you are troubleshooting, don’t rule out any possibility. For Microsoft, it really needs to improve the error messages and the mapping file validator.