Hello, premierdog. 

We'll encounter this error if the connection with our server was interrupted or corrupted. I have some steps you can perform so we can fix this. 

Let's first start by using an incognito window and connect it from there. You can also clear your browser's cache so the system can start fresh. Additionally, make sure that the browser is updated.  

If the same thing happens, you can switch to other supported browsers. It could be that the one you're currently working on has a temporary issue with QuickBooks Online.

Leave us a comment below if you have any other concerns or follow-up questions. The Community always has your back. Stay safe!