The attached file is Atahualpa3.7.25 - this release has one fix (thanks to kdawes01) that allows Atahualpa to run with WordPress 5.5
Note: development of Atahualpa in no longer on going and another change in WordPress could potentially cause another error. This fix has been minimally tested so be sure to backup your database and files before updating to this version.
Better yet, you should apply it to a test site and check things out before using it in production.
atahualpa3725.zip