Skipped columns - FirstName, LastName, Gender etc

Hi Experts, I'm trying to import historical data where during my initial load I was successful to import only X-Data and performed data & analysis with Stats IQ and Text IQ. Now I would like to combine X+O data by adding demographic information so that i can have a holistic view in my analysis. Currently when I'm importing the data, X data responses are successfully getting loaded, however the O data is getting skipped. ! Does anyone have an idea on how to load them? Currently I've no participants data created, since it's for a historical data, however the intention is to view the responses of the historic participants with their responses. I'm thinking quite few options here as well, like loading historic participants as well and then pull the information in data and analysis (if it works in this case). Appreciate if anyone can help me here :) Regards Pradyp