phraxos, I use turbo tax online and I amended my 2022 Fed and NY tax return. My experience was totally different from yours, but my experience was consistent each time. In your situation, it seems like you got to the end of the efile process and eventually got something that could be interpreted as an error message, like 'Transmission failed'. I never got that far. Each time when I would get to the screen that stated something like "let's get started to e-file your return", when I clicked continue, I would consistently get a popup box that stated something like "e-file is not available for amended returns and that I would have to print and mail my returns". It didn't seem like an error message, but rather a statement of fact.
