model->validate displays errors for text field which has value in yii - model-view-controller

Question

I have an application where user has to fill a lengthy form, so I split the form into three and created steps - Step 1, Step 2 etc. So it has to be convenient for users. Now I face a problem, after filling out the details, a text field shows an error. When using model->get Errors() the error is 'address cannot be blank'. When I use $_POST the arrays displays value for the field address. I started yii framework last week and I do not know where I have gone wrong. Any help appreciated.
The view code i use forloop to reduce my code -
<fieldset>
<?php if(!Yii::app()->user->hasFlash('success')):
Yii::app()->user->setFlash('warning','All Fields are mandatory!');
endif; ?>
<?php echo CHtml::errorSummary($model, null, null, array(
'class' => 'alert alert-danger col-lg-offset-2',
)); ?>
<?php $rrr = -1;
foreach($model->attributeLabels() as $a){ $rrr++;
if($rrr<27 && $rrr>=12){
?>
<div class="form-group">
<?php echo CHtml::activeLabel($model, $a, array('class' => 'col-lg-3 control-label')); ?>
<div class="col-lg-7">
<?php echo CHtml::activeTextField($model,array_keys($model->attributeLabels())[$rrr],array('value'=>'a','size'=>255,'maxlength'=>255,'class'=>'form-control formtype1')); ?>
</div>
</div>
<?php
}}
?>
<?php $rrr = -1;
foreach($model2->attributeLabels() as $a){ $rrr++;
if($rrr>1 && $rrr<6){
?>
<div class="form-group">
<?php echo CHtml::activeLabel($model2, $a, array('class' => 'col-lg-3 control-label')); ?>
<div class="col-lg-7">
<?php echo CHtml::activeTextField($model2,array_keys($model2->attributeLabels())[$rrr],array('value'=>'a','size'=>255,'maxlength'=>255,'class'=>'form-control formtype1')); ?>
</div>
</div>
<?php
}}
?>
<div class="form-group">
<div class="col-lg-offset-2 col-lg-10">
<button class="btn btn-sm btn-primary" type="submit"><?php echo Yii::t("user", "Submit") ?></button>
</div>
</div>
</fieldset>
</form>