I can't access the "uc-invoicepay" page under the store config menu:
Visit Admin -> Store -> Configuration -> Invoice Payment Form (or YOURDOMAIN.COM/admin/store/configuration/uc-invoicepay

When I access the page with the url mentioned above I get a "Access denied" message.

I replaced the store/configuration with store/settings but that didn't help.
I played around with the Global re-direct just in case that might have caused this issue. Right now I am out of idea.