Finalmente sono riuscito a capire perché continuava a visualizzare l'errore, era solo un problema di cache, una volta svuotata l'errore è scomparso.
Ora però sono nuovamente bloccato su di un'altro errore:
document type does not allow element X here; missing one of Y start-tag****
The mentioned element is not allowed to appear in the context in which you've placed it; the other mentioned elements are the only ones that are both allowed there and can contain the element mentioned. This might mean that you need a containing element, or possibly that you've forgotten to close a previous element.One possible cause for this message is that you have attempted to put a block-level element (such as "<p>" or "<table>") inside an inline element (such as "<a>", "<span>", or "<font>").
Line 23, column 4067: document type does not allow element "input" here; missing one of "ins", "del", "h1", "h2", "h3", "h4", "h5", "h6", "p", "div", "address", "fieldset" start-tag
?lue=='')this.value='la tua e-mail';" /> <input type="submit" value="»" c?
Line 23, column 4152: document type does not allow element "input" here; missing one of "ins", "del", "h1", "h2", "h3", "h4", "h5", "h6", "p", "div", "address", "fieldset" start-tag
?utton_invia" name="submitNewsletter" /> <input type="hidden" name="action" val?
Line 23, column 4200: document type does not allow element "input" here; missing one of "ins", "del", "h1", "h2", "h3", "h4", "h5", "h6", "p", "div", "address", "fieldset" start-tag
?ype="hidden" name="action" value="0" /></form></div></div></div><div id="cente?
Line 23, column 19643: document type does not allow element "img" here; missing one of "ins", "del", "h1", "h2", "h3", "h4", "h5", "h6", "p", "div", "address", "fieldset" start-tag
?.png" width="376" height="32" alt="" /><div class="low_footer">Tutti i prezzi ?
<div class="block_content">
<form id="search_form" action="{$link->getPageLink('index.php')}" method="post">
<input type="text" name="email" size="18" class="form_news" value="{if isset($value) && $value}{$value}{else}{l s='your e-mail' mod='blocknewsletter'}{/if}" onfocus="javascript:if(this.value=='{l s='your e-mail' mod='blocknewsletter'}')this.value='';" onblur="javascript:if(this.value=='')this.value='{l s='your e-mail' mod='blocknewsletter'}';" />
<input type="submit" value="»" class="button_invia" name="submitNewsletter" />
<input type="hidden" name="action" value="0" />
</form>
{if isset($msg) && $msg}
<p class="{if $nw_error}warning_inline{else}success_inline{/if}">{$msg}</p>
{/if}
</div>
Si tratta di un form per l'iscrizione alla newsletter, mi sembra di aver messo tutte le parti nelle posizioni giuste per continuo a ricevere l'errore.