Error in query editor

Hi gilbertendaya ,

 

That has to do with the column quality and usually you have a green or red bar indicating that you have errors in that column, can be formatting, calculations or other type of errors, but when you have very large datasets (lots of columns / lines) the quality of the column sometimes takes a long time to be checked or isn't performed so you get those lines.

 

Try to turn on the column distribution to check if it shows any errors.