Hello, JMAHanaska. 

The error you've encountered usually happens to the stored files in your browser. Sometimes an overloaded browser stops QuickBooks Online from working correctly. Open QuickBooks in a private or incognito window to see if the issue is with your browser. This can help us eliminate any cache-related problems that may have led to the issues. To open it, use the following shortcut keys: 

• Google Chrome: Press CTRL + Shift + N
• Safari: Press Command + Shift + N
• Mozilla Firefox: Press CTRL + Shift + P 

If the steps above are successful, I suggest clearing your browser's cache to eliminate outdated cookies. Some data stored on your browser can impact the transmitted data, resulting in unusual responses. 

If private browsing does not work, I recommend using a different browser. It will provide you with the best and most secure QuickBooks experience possible. For more information, please see this article: System Requirements For QuickBooks.    

Let me know in the comment section if you need further help. I'll be around to lend a helping hand. Stay safe and healthy always.