<asp:GridView ID="RolesView" CssClass="itemList" AutoGenerateColumns="false" runat="server">
                        <Columns>
                            <asp:TemplateField>
                                <ItemTemplate>
                                    <asp:CheckBox ID="RoleSelectedCheckBox" runat="server" />
                                </ItemTemplate>
                            </asp:TemplateField>
                            <asp:TemplateField HeaderText="Role">
                                <ItemTemplate>
                                    <asp:Label ID="RoleNameLabel" Text='<%# Eval("Name") %>' AssociatedControlID="RoleSelectedCheckBox" runat="server" />
                                </ItemTemplate>
                            </asp:TemplateField>
                            <asp:TemplateField HeaderText="Description">
                                <ItemTemplate>
                                    <asp:Label ID="RoleDescription" Text='<%# Eval("Description") %>' AssociatedControlID="RoleSelectedCheckBox" runat="server" />
                                </ItemTemplate>
                            </asp:TemplateField>
                        </Columns>
                    </asp:GridView>

AssociatedControlID="RoleSelectedCheckBox" is highlighted red even though it is perfectly valid.

Issue was closed