Hi there, @jfarbs.

In the new interface of QuickBooks Online accessing the contractor's page is now under Payroll in the left menu. And for the 404 error code that you encounter, it is likely related to a cache issue. We can isolate this by using an incognito browser as it doesn't use the existing cache data: 

• Google Chrome: Press CTRL + Shift + N.
• Safari: Press Command + Shift + N.
• Mozilla Firefox: Press CTRL + Shift + P.

Once an incognito window is open, log in normally and check the Contractors page. When the 404 error code doesn't show up, you can now start doing tasks for your contractors. Then, to resolve the issue completely, go back to the regular browser and clear the cache. 

To help you manage your contractors or vendors for the 1099 form, you can check this article: Understand which contractors need 1099s.

If you have any other concerns about QuickBooks or your contractors, let me know in the comment section. I'm always here to help.