I am unable to open all of the shared mailboxes I have access to in Outlook 2016. I get a message the .ost file is in use and cannot be accessed. Close any application that is using this file, and then try again. I am able to open 2 of the 5 that I have full access to. Has anyone else experienced this and if so how did you fix it?

Thank You in advanced for any help on this matter.

Hi Troy,

Currently, I'd recommend you post Office 2016 Preview related question in the following forum:

https://community.office365.com/en-us/office_2016_preview/f/

The reason why we recommend posting appropriately is you will get the most qualified pool of respondents, and other partners who read the forums regularly can either share their knowledge or learn from your interaction with us. Thank you for your understanding.

Steve Fan
TechNet Community Support