Fix the error-"The file username.ost is in use and cannot be accessed"

If you see the error message “The file username.ost is in use and cannot be accessed” and added into you might be wondering how to fix this error. Here, we’ll walk you through how to troubleshoot the problem yourself and what the error looks like, this is a known issue with MS Outlook. Also get to know the reasons for the occurrence of this issue.