Error when using Group by in a VIEW in Mysql

I created a VIEW to return the main data I need in a single query.

CREATE 
ALGORITHM = UNDEFINED 
DEFINER = 'root'@'localhost' 
SQL SECURITY DEFINER

VIEW v_historicoProcesso AS
SELECT p.protocolo AS protocolo
      ,p.der AS der
      ,p.data_habilitacao AS dhab
      ,a.descricao AS desandamento u.nome AS nome
      ,ap.bol_ativo AS ativo


  FROM (((processo p JOIN andamento_processo ap
        ON((p.id = ap.id_processo))) JOIN usuario u
        ON((u.id = p.id_usuario))) JOIN andamento a
        ON((ap.id_andamento = a.id)))
 ORDER BY ap.data DESC

So far the return has been satisfactory. Having the result something like:

  

123 2014-04-01 2014-02-02 agreed simao da silva S

     

123 2014-04-01 2014-02-02 agreed simao da silva N

     

123 2014-04-01 2013-02-02 agreed simao da silva N

     

456 2014-04-01 2014-02-02 without agreement jose da silva N

     

456 2014-04-01 2014-02-02 exigencia jose da silva S

     

456 2014-04-01 2014-02-02 input jose da silva N

I then made the following query:

SELECT protocolo
      ,der
      ,dhab
      ,desandamento
      ,nome
  FROM v_historicoprocesso
 WHERE ativo = 'S'
 GROUP BY idprocesso
 ORDER BY der       DESC
         ,protocolo ASC;

The result would be only the 'S' assets of each idProcess

  

123 2014-04-01 2014-02-02 agreed simao da silva S

     

456 2014-04-01 2014-02-02 exigencia jose da silva S

This query returned the following error:

  

Expression # 4 of SELECT list is not in GROUP BY clause and contains nonaggregated column 'v_historicoProcesso.desAndamento' which is not   functionally dependent on columns in GROUP BY clause; this is   incompatible with sql_mode = only_full_group_by

What is this error about? And what would be the best way to treat this query ?