If you are asking for help, I recommend you to make it as easy for others to be able to help you ...
You probably will get more feedback then...
which means in your case post a screenshot of your relevant blocks...
To download the aia file, upload it to App Inventor, open it, do some bug hunting for you, etc... this takes time, and most people will not do that...
Thank you.
You are looking at row 2 of returnData, which will have only one row.
Also, you are loading returned data into attributes like NumbersOnly and Multiline, which are true/false flags, instead of into .Text, which is always where the text data goes.
Gracias por el aporte, he realizado lo que me sugieres (incluyendo los atributos como NumbersOnly y Multiline) e igualmente en la Base de datos he cambiado la columna Carné (que estaba en la posición 2) a la número 1. Así he resuelto el problema y ha ejecutado bien.