Causes
- when the user conducting the migration, has insufficient privileges to access the PST file or when GSMME is unable to find or access the PST file. GSMME requires both read and write access to the PST file.
- If this happens for a root folder in the mailbox in an Exchange migration, then it’s usually a permission-related issue.
Fixes
Step 1: Ensure Administrator Has Full Access
Check whether the administrator has full access on the end-user mailbox.
Step 2: Create A New Administrator
You can also create a new administrator user in Exchange and give the account full mailbox access for all end-user accounts.
Step 3: Use New Account For Migration
Then, use the new account for the migration. You can delete the new administrator account after the migration is complete.