Error

The error is not related to conditional fields, but it means that you have something like this in your code:

<label>[text a] [text b]</label>

You can have only one square-brackety-thing between <label> and </label>

Hope that helps.

If you want you can set up your form here: https://conditional-fields-cf7.bdwm.be/form-tester/ and share the link so I can check for any other errors.

From looking at your code I see a couple of obvious HTML errors, for example this line:

<div align="left">Comentários</span><br>[textarea comments]</div>

You are closing a span element with </span>, but you didn’t open one. This is invalid HTML and will result in a hard-to-predict DOM structure, which in turn will cause all sorts of stuff to go wrong.

Contact Form 7 is a plugin that requires you to have a basic understanding of HTML structure and CSS rules. If you are not familiar with these, I would recommend you to either take a crash course, or switch to a more end-user oriented form plugin.

Best of luck!