I amended my return to change an asset purchased this year (an addition to an existing rental) from Section 179 to a depreciated asset. It did not change the refund amount because the rental had a loss, but it changed the amount of carryforward passive loss. When I tried to e-file the amended return, I got the error "The submission is a duplicate of one that was previously received". I tried transmitting the federal and CA state returns separately and the federal went through (and got accepted) but the CA return still triggers an error. My CA return also includes an LLC return that obviously did not change so perhaps it triggers the error. However, I don't know how to separate the LLC return from the CA state return. Moreover, CA did not allow the Sec 179 deduction in the first place and depreciated the asset so CA numbers did not change at all. I wonder if that may be causing the error. Any thoughts besides filing the amended return by paper? Thank you.