A customer has Office 365 and thus Outlook 2016 with all updates. Though she has Office 365, she uses Outlook only to access her Gmail account in addition to accessing old emails and old contacts that were long ago saved to two (2) independent .pst files, respectively. Everything worked fine until recently. She accessed her gmail, and had the two .pst files opened and accessible without problems.
Then 2 or 3 weeks ago when she opened Outlook she received an error message that the .pst files couldn't be opened (her words here, I don't have the specific error message unfortunately). Outlook still launched, but when she tried to access those PST files from the left folders pane as she normally would, she'd get that error message. So she closed them and tried to re-open (File/Open & Export/Open Outlook Data File... choose file, click [Open]). And gets the following error message:
"The <file path and name>.pst is not an Outlook data file (.pst)."
But of course it is a .pst file, both in name and contents, and has been used as one up until recently.
I of course can replicate this with both .pst files on her machine (a Surface 3, not that that matters)
I ran scanpst.exe on both and it found only minor problems, and I did the repair on those. On second, and third, and fourth.. run it finds nothing.
Thinking that perhaps the problem may be possibly a corrupt Outlook install, or perhaps an update (it was working fine until recently), I decided to try opening these files on a different computer with Office 365/Outlook 2016. Same problem.
These files I believe were originally created in Outlook 2007, but I am still at a loss for why that would matter. They were working just fine until a few weeks ago.
Did something change in Outlook 2016, perhaps in a recent update, that stopped supporting these files?
Both machines I tried the files on (and failed) were Windows 10, but again, both had been working on Windows 10 until a few weeks ago too. So I'm hesitant to think that has anything to do with the problem too.
* So, its two files, not just one
* Both files check out with scanpst.exe
* Everything was working until a few weeks ago, and then inexplicably stopped working
* Nothing is ever changed in these files (so I'm told). They are just old contacts and emails that are occasionally referenced
* The problem can be replicated on another machine with Outlook 2016 fully updated, and Windows 10 fully updated.
Any thoughts out there?