Open up the 2018 1065, mark the Efling amended box on the fed information worksheet, check the amended box on the front page of the 1065, make the changes and Efile it.

Under the new (for 2018 forward) centralized audit rules for partnerships... beware of the following:

https://www.irs.gov/e-file-providers/guidance-for-amended-partnership-returns

Perfect!  Thank you!

I did what you noted however, I still get the following message

"The version of ProSeries you are using is no longer current. Though this does not affect any returns you have already e-filed, you must update your tax program before electronically filing additional returns. To update your program, go to the Update menu and select 'Update Installed Products'. ProSeries will automatically download any updates available for currently installed products. After updating, you must also reconvert all files that are ready to transmit electronically. 

Not transmitted, the amended return(s) failed the tax submission amended return validation step. Please make the necessary corrections."

I updated the installed products and reconverted the file and still does not work.

If you did the "update installed products" and you still get the message that you need to update, try one of these other methods for updating.

I have the same problem...did you ever get this fixed?

The 2018 amended 1065 will not transmit but no explanation. Also same message with 2018 1120S