OST file is bound to the specific profile and Its access can be only done when you log in and authenticate using the profile originally used to create an OST file. You can migrate from offline ost to pst, if your Exchange Server is up and connectivity of MS Outlook with MS Exchange is working properly. You need to follow below procedures:
Open Microsoft Outlook >> File >> Import and Export >> Export to a File >> Personal Storage Table File >> Select the Mailbox folder which you want to export >> provide the location to save pst file and finally click on “finish” .
You can delete the local OST file and recreate the OST files with Outlook from scratch when the connection between the Microsoft Exchange Server and the Outlook user’s profile is available. This newly created OST file will synchronize with Exchange Server’s mailboxes data. This newly created file will produce no error. But you have already told that you have used this technique, then there might error in your ost file.
Hence you can use OST Integrity Checker Tool(scanost.exe) or Inbox repair Tool (scanpst.exe)depending on the versions of Outlook to repair ost file after that use “First Technique” to migrate from OST to PST. You can also use any reliable OST Repair tool to do the same task.