I get the error message when trying to upload from bank: Cannot read properties of null (reading 'getMonth')?

Thanks for sharing your concern with us, Lion Laura M. 

Let me share some basic troubleshooting to help resolve this. I want to make sure you can get past this error.

If you haven't tried some troubleshooting steps, let's do that to rule out any browser-related issues. It helps fix your browser to work better and faster.

Most common issues in QuickBooks Online are usually the result of outdated or corrupt cache files in your web browser. Let's try accessing your account through an incognito window to rule out the possibility of a webpage issue. You can refer to these shortcut keys to open an incognito window in all supported browsers:

• Chrome: Ctrl+Shift+N
• Firefox: Ctrl+Shift+P
• Safari: Command+Shift+N

If you're not getting the same message, I recommend clearing the cache of your regular browser so you can access QuickBooks with a clean slate. You may also use a different supported one.

Visit me here again in the Community and let me know the result after performing the steps above. I'm determined to help you succeed.

I no longer get the error message, and I tried your suggestion about going incognito. Bank account still won't update. Two out of the three that is. I've inspected the metadata in regular mode, and I don't find anything different about those two accounts that would suggest why they wouldn't update. They are linked to the bank correctly... 

I tried your suggestion and went  incognito, and my bank accounts still wouldn't update. Two out of the three, but one does update. Very strange. I checked the metadata and I don't see any obvious reason why they wouldn't update, or why the other one did. I don't get the error message anymore, they just won't update. Please advise.

Thanks for following up on this, Laura.

It's good to know you've followed the steps shared by my colleague above and rectified the error. Accessing your account using a private or incognito window detects issues related to your browser and improves program performance. However, since there are still accounts that won't update, I can share additional troubleshooting steps so you can get back to working order. 

Before we proceed, may I know what specific bank institution are you having issues with? This way, I'll be able to check if there are related issues with your financial institution.

For now, we can try running the manual update to refresh the connection between QuickBooks and your bank. This updates all your connected bank and credit card accounts.  I'll show you how:
 

1. Open your QuickBooks Online account.
2. Go to the Banking menu.
3. Select Update.

If the accounts still won't update even after doing the steps above, I recommend reaching out to our QuickBooks Support Team so they can look into this issue further. They have all the necessary tools to pull up your account securely and find out the root cause of this. Here's how you can contact them:
 

1. Go to the Help icon in the top right-hand corner.
2. From there, click on Search, then click the Contact Us button.
3. Enter your question in the box and hit Continue.
4. Choose the best way you'll want to reach out to us.

 They can only accommodate you Mondays to Fridays from 6 AM to 6 PM PT and Saturdays from 6 AM to 3 PM PT.

In case you encounter online banking errors in the future, utilize this article for reference on what to do: Fix specific bank errors.

Once everything is fine on your end, it's best to review and categorize your downloaded bank transactions and put them in the right accounts.

I hope this information helps. Let me know in the comments below if I can be of additional assistance. I'll be around to lend a hand.