In addition to @Quentin's answer, this issue also occurs when the for attribute in your <label> element does not reference any <input>, or <select> element id

For example:

<label for="filter">Filter Options</label>
<select name="filter">
  <option value="asc">Ascending</option>
  <option value="desc">Descending</option>
  <option value="def">Default</option>
</select>

To fix this, make sure, the input or select element id matches with the for attribute.

Essentially:

<label for="filter">Filter Options</label>
<select name="filter" id="filter"> <!-- id="filter" now references for="filter" -->
  <option value="asc">Ascending</option>
  <option value="desc">Descending</option>
  <option value="def">Default</option>
</select>