After upgrading my QB account I lost all of the bank register detail. Now when I download and book the current activity the bank register is still not populating.
I understand the urgency to view your bank register detail, @john138.
Let's run the Rebuild and Verify Utility tool. This will automatically fix any potential data issues with your company file so you can access your bank registers in no time.
Go to the File menu.
Choose Rebuild Data.
Go back to the File menu.
Choose Verify Data.
If the issue persists, you can continue performing other solutions provided in this article: Fix data damage on your QuickBooks Desktop company file. It contains four sets of solutions. You can start executing the suggested steps in Solution 2: Repair your company file using QuickBooks File Doctor section.
Moreover, you can also use your backup company file to restore your accounting data. This way, you'll be able to start using your data that contains all your bank registers. For the detailed steps, kindly refer to this article:
Restore a backup of your company file. It also contains an important reminder about moving your backup company file to your local hard drive id you're using an external device in saving it.
Please let me know if you have other concerns. I'm just around to help.