When I go to add a new bill the 'Terms' drop down has no options any longer, when will these terms such as 'Net 30' return?

Well 'Payment Methods' are gone as well. And I can't create new ones with the same name as it says it's already created. 

My ability to use QBO has completely halted, can't add expenses or bills. 

Let's resolve the error you're having to create a bill successfully, @cullen1.

This error can be caused by your browser. A regular browser's cache stores temporary internet files from your browsing history. However, as it collects too many files, this may cause performance issues in your account. This might be the reason why you're having trouble with your terms and payment method. 

I've got some steps to help fix this issue. First, you'll have to sign in to your QBO account using a private browser. This helps isolate the issue since it doesn’t store data in the cache. Here are the following keyboard shortcuts: 

• Safari: Command + Shift + N
• Mozilla Firefox: CTRL + Shift + P
• Google Chrome: CTRL + Shift + N 
• Microsoft Edge:  CTRL + Shift + P

If it works, here's how to clear cache and cookies to fix issues when using QuickBooks Online. Restart your browser right after. 

You can also try to create a bill using other supported browsers (Firefox, Google Chrome, Safari, Microsoft Edge) if the steps above didn’t work.

You can refer to the following article for more information about tracking your bills and recording payments: Enter bills and record bill payments in QuickBooks Online.

Refer to the following article for more information on how to record billable expenses. This is an expense you incur on your customer’s behalf when you perform work for them: Enter billable expenses.

Let me know if there's anything else that I can help in creating a bill and by leaving a reply below. Take care and have a wonderful day!