Package Install

Install from the Current Version Package Installation Link above.

Do not Deploy this package until you have finished the post-install config. Run the installation, but choose Deploy Later.

Post-install Config

Activate all inactive contact owners prior to converting a particular account.
If you are using account record types, the newly created one-to-one accounts will default to the converting user's default account record type. Make sure the user performing the conversion has the desired individual record type set as their default prior to the conversion.
Run a report to identify opportunities with account = <converting from account> and no primary contact role identified. Those opportunities will fail to convert.