Invalidate negotiated settled because of errors of fact?

is it possible to invalidate a signed and notarized negotiated settlement? because of errors of fact? because one attorney failed to provide a consultation before the negotiation? (is that cause for complaint against the attorney?) Is there any ground for invalidating a signed and notarized negotiated settlement? And, if so how does one go about it?
Thank you.

Separation agreements are almost impossible to have rescinded. The lawyer’s failure to properly explain the terms is not cause to rescind the agreement as the parties are presumed to have signed the same voluntarily.

Thank you. How about errors of fact? e.g., an asset was included for division that was not actually an asset (it was the attorney’s error to include it) and another asset was not included that should have been.

You may attempt a rescission based on a mutual mistake of fact ( both parties did not realize the mistake at the time the agreement was signed).