How can I get rid of this firefox console warning?

Question

I get this css warning on the browser (firefox) console when I open my web page:

Expected ‘none’, URL, or filter function but found ‘alpha(’. Error in parsing value for ‘filter’. Declaration dropped. materialize.min.css:13:42355

Elements matching selector: .file-field input[type="file"]

NodeList [ input#galleryFile ]

Here is snippet about the gallery file:

  <div id="modal-gallery" class="modal grey">
        <div class="modal-content center-align">
          <h4>Gallery</h4><br/>
          <div class="gallery"></div>
            <div class="container">
              <div class="file-field input-field">
                <div class="btn blue">
                  <span>Upload Photo</span>
                  <input id="galleryFile" />
                </div>
              </div>
            </div>
        </div>
      </div>

I do not like seeing errors or warnings on the browser console when inspecting my web pages. If there is any one that could suggest what should I do to clear this warning, please now is the time I wish to hear your input.

Thanks

Answer 1

Expected ‘none’, URL, or filter function but found ‘alpha(’. Error in parsing value for ‘filter’. Declaration dropped.` materialize.min.css:13:42355`

Elements matching selector: .file-field input[type="file"]

NodeList [ input#galleryFile ]

As the error says is not from your HTML5 file. The error comes more in to the code itself.

materialize.min.css:13:42355, nothing to worry about.