Updating Custom Fields in User info with the Import Users Tab

Hi I’m having a problem updating a few Custom Fields I created for my users. I’m using the Import template spreadsheet provided by iiQ. I am matching the iiQ users up with their ID number and omitting the first name and last name, email, usernames fields. But I’m getting this error “listed below”. I didn’t think that I need to include the users: emails, names, and usernames when updating to a Custom Field and matching just the ID numbers?

Any help you can provide would be appreciated

Ps: Is there a way to copy error information to the clipboard because I see that I might have not gotten all of it. hence the … at the end of the error code

:: Error executing Sql because 'Cannot insert the value NULL into column 'FirstName', table 'iiq-prod-sqldb.dbo.Users'; column does not allow nulls. INSERT fails.'; at jLib.Db.SqlHelper.ExecuteX(DbConnection SqlConnection, CommandType CommandType, String Command, OrderedDictionary`2 Parameters) at jLib.Db.SqlHelper.ExecuteX(CommandType CommandType, String Command, OrderedDictionary`2 Parameters) at jLib.Db.DataFramework.BaseTableRecord`1.Save[T](SqlHelper SqlHelper, T AuthorId, SaveOptions Options) at Spark.Data.BaseTableRecordImpl`1.Save[T](SqlHelper SqlHelper, T AuthorId, SaveOptions Options) in F:\Jenkins\Workspaces\incidentiq.com - Webdeploy\Spark.Data.Framework\BaseTableRecordImpl.cs:line 135 at Spark.Data.User.Save[T](SqlHelper SqlHelper, T AuthorId, SaveOptions Options) in F:\Jenkins\Workspaces\incidentiq.com - Webdeploy\Spark.Data\Tables\Users.cs:line 46 at jLib.Db.DataFramework.BaseTableCollection`4.Save[T](SqlHelper SqlHelper, T AuthorId, SaveOptions Options, Cancella...