I ran into this one yesterday. I was attempting to export a PST file with the findings of a compliance search within Office365. I couldn’t run it on my computer, nor the server where I was offloading the PST to. The error I got was simply “Make sure the export content hasn’t expired”.
Helpful. It obviously hadn’t expired.
Eventually I did the following: First, I started using Internet Explorer to do the export. Next, I found this Microsoft help doc that stated to add the following websites to the trusted or intranet zone in IE.
*.outlook.com, *.office365.com, *.sharepoint.com and *.onmicrosoft.com are added to the Local intranet zone trusted sites.
Voila! That did the job and my PST downloaded nicely.