My ListView is raising events that don't exist - asp.net

Question

So I have a listview:
<asp:listview runat="server" ID="listview_search" itemPlaceholderID="itemListing" DataSourceID="ds_search">
<LayoutTemplate>
<div id="sort" runat="server">
<asp:LinkButton runat="server" id="sortByPrice" CommandName="sort" CommandArgument="price" >Sort by price</asp:LinkButton>
</div>
<div runat="server" id="itemListing"></div>
</LayoutTemplate>
<ItemTemplate>
<div class="container profilelistings">
<div class="row carousel-row">
<div class="col-xs-8 col-xs-offset-2 slide-row" style="min-height: 100px;">
<div id="carousel-1" class="carousel slide slide-carousel">
<div class="carousel-inner">
<div class="item active">
<asp:Image id="img_car" imageurl='<%# "images/" + Eval("ownerID") + "/" + Eval("photo1") %>' runat="server"></asp:Image>
</div>
</div>
</div>
<div class="slide-content">
<h5><%# Eval("make").ToString() + " " + Eval("model") + " (" + Eval("type") + ") " %></h5>
<h5><span class="price"><%# "£ " + Eval("price") %></span></h5>
</div>
<div class="slide-footer">
<span class="pull-right buttons">
<button class="btn btn-sm btn-default"><i class="glyphicon glyphicon-eye-open"></i> View more info </button>
</span>
</div>
</div>
</div>
</div>
</ItemTemplate>
</asp:listview>
When I click the sortByPrice LinkButton it gives an error "The ListView 'listview_search' raised event Sorting which wasn't handled." When the event does not exist in the ListView itself nor in the code.
Does anyone understand why it is doing this?