in your WordPress dashboard. The file you uploaded via FTP will appear there. Click Restore : Select "Restore" on that file to begin the migration. 3. Editing Plugin Core Files (Use Caution)

Use a Wired Connection: If you are uploading via a browser, do not use Wi-Fi. A single momentary drop in connection can corrupt a 100GB upload.

This error indicates that the .wpress file you are trying to import is corrupted or incomplete.