Why does column mapping work only for some columns?

Please check that the column you are mapping to has a space in the column name or a special character.


The column's internal name is used for performing the column mapping therefore the column mapping list needs to have the column's internal name specified.
If the column has a space in the name SharePoint uses the characters "_x0020_" to represent a space so you need to specify this in the column mapping list when entering the 'To Column' names as below:

 

The table below represents examples of characters that could be in a column's internal name and how to represent them in the column mapping list:

space

 _x0020_

 &

 _x0026_

 '

 _x0027_

 -

 _x002d_

 {

 _x007b_

 }

 _x007d_