Follow documentation at  to export installation settings from existing Ops Manager and then import it to new deployed Ops Manager, get error message "Installation file cannot be decrypted".
Pivotal Cloud Foundry®
Load an installation.zip that was encrypted with a different password than the current one you are using. It usually means that the password you used for new Ops Manager user is different than the password you used for old Ops Manager user.
You can input the encryption password to decrypt the zip file by clicking "Need to enter a decryption password" and adding password.