Error: SyntaxError: Unexpected end of JSON input APEX 5.1 - oracle-apex

Question

I have this problem:
I have this JavaScript code in a Dynamic Action:
var vMe = $(this.triggeringElement);
var vRow = $(vMe).parents(".meAllRow");
var vSeqID = $(vRow).find("[headers=SEQ_ID]").html();
var vEstado = $(vRow).find("[name=f01]").val();
apex.server.process("ajx_Cambia_estado",{x01:vSeqID,x02:vEstado});
and this is the PL-SQL CODE
DECLARE
vEstado VARCHAR2(1);
vSeq NUMBER := to_number(APEX_APPLICATION.g_x01);
BEGIN
IF (APEX_APPLICATION.g_x02 = 'A') THEN
vEstado := 'I';
ELSE
vEstado := 'A';
END IF;
APEX_COLLECTION.UPDATE_MEMBER (
p_collection_name => 'DINAMIC_LIST',
p_seq => vSeq,
p_c002 => vEstado);
END;
When I execute the dynamic action, it throws this error:
SyntaxError: Unexpected end of JSON
but when I put a return in the PL-SQL like:
htp.p('"process":"finish"');
the error disappears. But I don't need to send a response message, in Apex 4.2 I don't have this problem.

Answer 1

Try:
DECLARE
vEstado VARCHAR2(1);
vSeq NUMBER := to_number(APEX_APPLICATION.g_x01);
BEGIN
IF (APEX_APPLICATION.g_x02 = 'A') THEN
vEstado := 'I';
ELSE
vEstado := 'A';
END IF;
APEX_COLLECTION.UPDATE_MEMBER (
p_collection_name => 'DINAMIC_LIST',
p_seq => vSeq,
p_c002 => vEstado);
apex_json.open_object;
apex_json.write('success', true);
apex_json.close_object;
END;