Fix QB2012 History Retention Issue

I'm experiencing an issue with QuickBooks 2012 for Mac, where all types of history (transaction, customer, and vendor) are not being retained. This problem has occurred without any recent changes on my part.

Key Requirements:
- Diagnose and fix the history retention issue
- Ensure stability and integrity of the data
- Provide guidance on preventing future occurrences

Ideal Skills and Experience:
- Expertise in QuickBooks, especially the 2012 Mac version
- Strong troubleshooting skills for offline software
- Experience with data integrity and retention issues