The "Outlook data file cannot be accessed" error typically results from corrupted or misplaced data files. First, to resolve this issue, use the Inbox Repair Tool (ScanPST.exe) to locate and repair the problematic data file. If the issue persists, create a new Outlook profile through the Control Panel's "Mail" settings and import the repaired data file into this new profile. If necessary, consider restoring a data file backup to recover any lost information. Always regularly back up your data files to prevent data loss and simplify recovery processes. https://www.limksys.com/outlook-data-file-cannot-be-accessed/