Let's determine why you're unable to send an invoice, kennethfrancois1.
There are times that an issue like this occurs when we encounter browser-related issues. To fix this, let's try sending an invoice on a private window. This is the best place to identify any browser-related concerns.
You can use these keyboard shortcuts to open one:
Google Chrome: Ctrl + Shift + N
Mozilla Firefox: Ctrl + Shift + P
Microsoft Edge: Ctrl + Shift + P
Safari: Command + Shift + N
If you're able to send one, you can go back to a regular browser and clear its cache. A piled cache can also trigger some unexpected behavior on the opened pages.
You also have the option to switch to a different browser like Google Chrome, Mozilla Firefox, Microsoft Edge, or Safari.