It looks like the "invalid credentials" issue with Quickbooks online has resurfaced AGAIN.
I'm extremely disappointed. This issue first came up in August and lasted about 1.5 months and was finally resolved. Everything was working fine until 3 days ago when I started receiving the "invalid credentials" error again. I'm disappointed because I know now I can't rely on this tool; I have to go back to my client and tell them I can't deliver their promised reports.