As a part of a DR test today, I recovered the encrypted database (log shipped) and restored the service master key from the production. When restoring the key, the following error showed up:
Msg 15320, Level 16, State 12, Line 1
An error occurred while decrypting master key 'DbName' that was encrypted by the old master key. The FORCE option can be used to ignore this error and continue the operation, but data that cannot be decrypted by the old master key will become unavailable.
Use the FORCE option. Although the documentation says that you might lose some data, as long as you have the correct service master key from the production, that will not happen. Quite the contrary, the correct master key will decrypt the database.
Tags: SQL Server error 15320, service master key, restore