I am unable to create an invoice. The response is unable to connect to server. I am able to see previous invoices and record payments.

Hello there, @matt248. I'm here to ensure you can seamlessly create your invoices in QuickBooks Online. 

Sometimes, the browser's cache can become filled and cause issues when working your QuickBooks Online (QBO) account. I suggest running QBO in a private or incognito browsing mode to help your computer run optimally and regain some storage space to continue working seamlessly.

You can use these keyboard shortcuts to open incognito or private mode: 

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

Also, you can try clearing your browser's cache so the system can restart and use an updated browser to run QBO effectively.

If you want to customize your sales forms in QBO, you can visit this article for reference: Customize invoices, estimates, and sales receipts in QuickBooks Online.

Feel free to contact us if you have further inquiries about creating invoices in QBO. I'll be of help. Have a fantastic day!