How to edit an existing invoice? The Veiw/Edit function doesn't seem to work, goes into the spinning thinking mode but will not proceed past that.

I got you covered, @william-fagan-ve. Let's take some steps to make sure editing an existing invoice will be easy. 

In QuickBooks Online (QBO) the spinning error you encounter is sometimes caused by a browser issue. Accessing your account in an incognito mode is the initial fix to this. 

Below are the keyboard shortcuts that you can use depending on your browser type:

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

Once signed in, edit the existing invoice again.  If you successfully perform the action, I recommend clearing the cache of your regular browser. This will remove and delete the damaged cache and cookies that caused the error. If you're unable to do so, you can use another supported browser or device as an alternative. Maybe the current one you're using has a temporary issue with QBO.

Customizing your sales forms such as invoices is a breeze in QBO. You can add or remove details or change the color to further express what your business is all about. To get started, simply go to the Gear icon and select the Custom Form styles feature.

I'm always happy to assist you in case you have additional questions about editing your invoice. Feel free to post a reply below and I'll circle back to lend a hand. Have a wonderful day.