There are manual methods available to fix the ‘Outlook is using an old copy of your data file’ error. But the best method is automated, the SysInspire PST Converter software is an automated third-party tool. They can resolve your Outlook errors within seconds. You can use it on all versions of Windows OS. This software converts your PST file into 13 plus formats and recovers your mailbox items which include email, contacts, calendar, and appointments.
Read more:-‘Outlook is using an old copy of your data file’ error Fixed
The steps are as follows,
Close Outlook program and then navigate to OST file location based on Windows OS
Find the problematic .OST file
Copy the .OST file and save it on an external or different drive safely
Now delete the .OST file and then start the Outlook
Hope This Helps,
Peter