Has anyone been able to connect their Acorns.com account?

Thanks for letting us know about your situation, erandall.

If you can log in to your bank's website without a problem, and all the prompts are acknowledged, then I'll share a different solution that you can try. 

Let's do some troubleshooting steps on your browser. You might have some corrupted file cache that is causing this error. To start, open your QuickBooks Online account in a private browser or incognito. This mode prevents your browsing history from being stored. You can use the keyboard shortcuts below: 

• Google Chrome: Ctrl + Shift + N
• Mozilla Firefox: Ctrl + Shift + P
• Safari: Command + Option + P

Next, try to connect your bank. If you can connect without the error, let's go back to your regular browser and clear its cache. Finally, restart your browser to refresh the settings.

On the other hand, try using a different supported browser.  

You also have the option to import your bank transactions manually. The steps are included in this article: Manually upload transactions into QuickBooks Online. If you ever encountered issues with importing the transactions, you can perform some of the troubleshooting steps here. 

Please let me know of the result after trying out the steps above. I'd also like to know what's the name of your bank, so I can check if there's a reported issue. You can leave a reply below and I'll get back to you as soon as I can. Stay safe!