it.toLowerCase is not a function

typeahead.css

ul.typeahead.dropdown-menu {
  position: absolute;
  top: 100%;
  left: 0;
  z-index: 1000;
  display: none;
  float: left;
  min-width: 160px;
  padding: 5px 0;
  margin: 2px 0 0;
  list-style: none;
  font-size: 14px;
  text-align: left;
  background-color: #ffffff;
  border: 1px solid #cccccc;
  border: 1px solid rgba(0, 0, 0, 0.15);
  border-radius: 4px;
  -webkit-box-shadow: 0 6px 12px rgba(0, 0, 0, 0.175);
  box-shadow: 0 6px 12px rgba(0, 0, 0, 0.175);
  background-clip: padding-box;
}
ul.typeahead.dropdown-menu.pull-right {
  right: 0;
  left: auto;
}
ul.typeahead.dropdown-menu .divider {
  height: 1px;
  margin: 9px 0;
  overflow: hidden;
  background-color: #e5e5e5;
}
ul.typeahead.dropdown-menu > li > a {
  display: block;
  padding: 3px 20px;
  clear: both;
  font-weight: normal;
  line-height: 1.42857143;
  color: #333333;
  white-space: nowrap;
}
ul.typeahead.dropdown-menu > li > a:hover,
ul.typeahead.dropdown-menu > li > a:focus {
  text-decoration: none;
  color: #262626;
  background-color: #f5f5f5;
}
ul.typeahead.dropdown-menu > .active > a,
ul.typeahead.dropdown-menu > .active > a:hover,
ul.typeahead.dropdown-menu > .active > a:focus {
  color: #ffffff;
  text-decoration: none;
  outline: 0;
  background-color: #337ab7;
}
ul.typeahead.dropdown-menu > .disabled > a,
ul.typeahead.dropdown-menu > .disabled > a:hover,
ul.typeahead.dropdown-menu > .disabled > a:focus {
  color: #777777;
}
ul.typeahead.dropdown-menu > .disabled > a:hover,
ul.typeahead.dropdown-menu > .disabled > a:focus {
  text-decoration: none;
  background-color: transparent;
  background-image: none;
  filter: progid:DXImageTransform.Microsoft.gradient(enabled = false);
  cursor: not-allowed;
}
.open > ul.typeahead.dropdown-menu {
  display: block;
}
.pull-right > ul.typeahead.dropdown-menu {
  right: 0;
  left: auto;
}
.dropup ul.typeahead.dropdown-menu,
.navbar-fixed-bottom .dropdown ul.typeahead.dropdown-menu {
  top: auto;
  bottom: 100%;
  margin-bottom: 1px;
}
@media (min-width: 768px) {
  .navbar-right ul.typeahead.dropdown-menu {
    left: auto;
    right: 0;
  }
}
ul.typeahead.dropdown-menu a,
ul.typeaheadul.typeahead.dropdown-menu a {
  text-decoration: none;
}