You're on the right path by creating a backup file first, jrdaneke.
Before proceeding, could you please share the error messages you've encountered? Any details or screenshots you can provide would be helpful.
Meanwhile, condensing company files primarily impacts reports, such as the audit trail and reconciliation reports, rather than banking processes. If the deposit is linked to a closed account, it shouldn't affect current banking. However, be mindful of any accounts associated with the deposit and reports referencing historical data.
Now, given you already have a backup of your company file, please review the 2008 deposit transaction and its details, including linked accounts and customers. This will help you assess the risks of removing it.
Remember to reconcile all accounts and print or save all reconciliation and discrepancy reports in PDF format before using the condense file utility. I'll include this article with tips for streamlining your company data file and boosting performance: Use the Condense Data utility.
Here's an article you can browse to learn about the maximum number of list entries in QuickBooks Desktop: Maximum number of list entries (list limits and custom fields).
The Community and I will be here if you have follow-up questions during this process.
