Can not make an invoice for some reason, says can't connect to our server....

Hello there, Mark. I know how important it is to have a seamless process when creating invoices. 

First, let's make sure that you're connected to a strong connection. If the issue continues, let's open your QuickBooks account in a private window to rule out browser-related issues. Here are the keyboard shortcuts:

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

If you can successfully create an invoice, return to your regular browser and clear your cache. Occasionally, the accumulated cache and cookies in the system can become outdated or corrupted, leading to unexpected behaviors. You can also switch to other supported browsers that installed, which is a good alternative.

Once you successfully create an invoice and received a payment from your customer, you can record it in QuickBooks to marked the invoices as paid. 

Just tap the reply button below if you need further assistance managing your invoices in QuickBooks Online. I'm always here to lend a hand, Mark.