Hi, thank you for contacting JustAnswer.com. My name is Russell. I will do my best to provide the right answer to your question.
Have you also, in the last year, perhaps updated the MAC OS X version from 10.8 or earlier? that could cause the problem, perhaps.
Is the 'different hard drive' you've been using, an external hard drive? in case that detail matters to the case...
Let me know, please. Thanks.