Outlook - Your Outlook data file cannot be configured error when enabling cached exchange mode

Question

Hi,

I recently upgraded one of our user's Office from 2013 to Office 365 Pro Plus. After the upgrade I couldn't launch his Outlook anymore. After hours and hours of troubleshooting, I found out that it wouldn't open when I have cached Exchange mode enabled. It's strange because even if I delete all the outlook profiles and create a new one it still wouldn't work when cached mode is enabled. 

Whenever I enabled cached exchange mode it says "Your Outlook Data File Cannot Be Configured" then it gives the path to the .ost file which is in C:\users&lt;username>\AppData\Local\Microsoft\Outlook&lt;user email>@<domain>.ost

The mailbox is 36.5 GB in size so it's a bit sluggish running it without the cached mode enabled.

I've also tried outlook.exe /resetnavpane but that didn't fix the problem. Disabling all add-ins also didn't help. 

Do you guys have any suggestions?

Answer 1

Hi Paolo777,

Have a good day. This is Alan Wu from Office 365 forum support. 

Under the current situation (your description), the issue is mostly like to be related to the Outlook .OST data file since the error indicated the path to your .OST data file. So, please try repairing your Outlook data file via the instruction of https://support.office.com/en-us/article/Repair-Outlook-Data-Files-pst-and-ost-25663bc3-11ec-4412-86c4-60458afc5253. 

If you have done this and the issue persists, please try https://support.microsoft.com/en-us/help/4098558/how-to-scan-outlook-by-using-the-microsoft-support-and-recovery-assist. It will generate the report if some problem is detected. If so, please provide the complete information in the Private Message (PM) for checking. Note: This tool applies to Office 365 account. So you are using the Office 365 account, right?

Also, you can firstly back up the Outlook data and then compact your mailbox. After that, re-import the data into your Outlook mailbox to see if it makes a difference. You may refer to back up mailbox data in Outlook and compact mailbox in Outlook. 

We are always here for you. 

Regards,

Alan

Answer 2

Hi Paolo777,

If you got an update about this case, please share it with us. We are always here for you. 

Regards,

Alan