uploading multiple images from the frontend using FAL in TYPO3 /extbase

Question

I am using this Helhum example for uploading images from the frontend, which is located on the following link

 https://github.com/helhum/upload_example

If we check its form fields in partial file on location https://github.com/helhum/upload_example/blob/master/Resources/Private/Partials/Example/FormFields.html

there is given two uploads option which are following

 {namespace h=Helhum\UploadExample\ViewHelpers}
 <label for="title">
 <f:translate key="tx_uploadexample_domain_model_example.title" /> <span class="required">(required)</span>
</label><br />
<f:form.textfield property="title" /><br />
<label for="image">
<f:translate key="tx_uploadexample_domain_model_example.image" />
</label><br />

 <h:form.upload property="image" >
    <f:if condition="{resource}">
        <f:image image="{resource}" alt="" width="50"/>
    </f:if>
</h:form.upload><br />
<label for="image_collection">
<f:translate key="tx_uploadexample_domain_model_example.image_collection" />
</label><br />

Here for the property="imageCollection.0" if I make it multiple="multiple" then it give me the following error

1297759968: Exception while property mapping at property path "imageCollection": PHP Warning: spl_object_hash() expects parameter 1 to be object, null given in /var/www/webroot/typo3_src-7.6.14/typo3/sysext/extbase/Classes/Persistence/ObjectStorage.php line 155 (More information)

And if I remove the 0 and just try to click a botton then it even not generate a form and give me the following error

1297759968: Exception while property mapping at property path "": The source is not of type string, array, float, integer or boolean, but of type "object" (More information)

So long story in short, how can I fix this example for multiple images uploading. I try to used without helper function just used a standerd fluid function <f:form:upload> it still give me a same error. please somebody can help me in sort out this problem.