Symptoms
When you create a package the dependencies of the process show that they cannot be packaged:
Error: - 'Workflow' Process is referencing the 'Missing ConditionID: ' ' Unknown that could not be found.
Diagnoses
This error can be caused be modifications to the workflow activities contained in the process. Also, on the dependencies screen the specific activity's were referenced by the error message.
Resolution
To resolve this error re run the activity wizards in the workflow and redeploy the workflow as per the instructions on contained within the error message. After which the errors should be resolved.