Inline errors with Freeform composer

Question

I would like to show inline errors on my composer form in Freeform. I tried the template code mentioned at https://expressionengine.stackexchange.com/a/25346/961 which is:

<p>
    {composer:field_output}

    {!-- composer:field_name will parse first to the field's name --}
    {if freeform:error:{composer:field_name}} 
        <strong>{freeform:error:{composer:field_name}}</strong>
    {/if}
</p>

but it's giving me the error:

You have an invalid conditional in your template. Please review your conditionals for an unclosed string, invalid operators, a missing }, or a missing {/if}.

Parser State: Unexpected ‘:’ (MISC); expected RD in on line 28.

If I remove the inline error code then it works ok but obviously doesn't show the inline errors.

The full composer template is as follows:

<div class="ff_composer">
{composer:page}
    {composer:rows}
            <div class="line">
        {composer:columns}
                <div class="unit size1of{composer:column_total}">
                {if composer:field_total == 0}
                     
                {/if}
            {composer:fields}
                {if composer:field_label}
                    {if composer:field_type == 'nonfield_captcha'}
                        {if freeform:captcha}
                        <p>
                            <strong>{composer:field_label}</strong>
                        </p>
                        {/if}
                    {if:else}
                        <label class="field_label" {if composer:field_name != ''}for="freeform_{composer:field_name}"{/if}>
                            {composer:field_label}{if composer:field_required}<span class="required_item">*</span>{/if}
                        </label>
                    {/if}
                {/if}
                {if composer:field_output}
                    {if composer:field_type == 'nonfield_title'}
                        <h2>{composer:field_output}</h2>
                    {if:elseif composer:field_type == 'nonfield_paragraph'}
                        {composer:field_output}
                    {if:elseif composer:field_type == 'nonfield_captcha'}
                        {if freeform:captcha}
                                {freeform:captcha}<br />
                                <input type="text" name="captcha" value="" size="20" maxlength="20" style="width:140px;" />
                        {/if}
                    {if:else}
                        <p>
                        {composer:field_output}
                            {!-- composer:field_name will parse first to the field's name --}
                            {if freeform:error:{composer:field_name}} 
                                <strong>{freeform:error:{composer:field_name}}</strong>
                            {/if}
                        </p>
                    {/if}
                {/if}
            {/composer:fields}
                </div>
        {/composer:columns}
            </div>
    {/composer:rows}
{/composer:page}
</div>

Answer 1

For EE3, it appears that Freeform 5.x is a bit fussier about the conditional. Try this code instead:

<p>
    {composer:field_output}

    {!-- composer:field_name will parse first to the field's name --}
    {if "{freeform:error:{composer:field_name}}"}
        <strong>{freeform:error:{composer:field_name}}</strong>
    {/if}
</p>