I see a couple of things that look a bit off:

• Your select element's closing tag seems to be a script closing tag
• Only use @ when you're outputting something to the markup, example: no need to use this in your foreach()

• Your Model.Children.Where() seems a bit odd, perhaps you're looking to do something like:

  foreach (var subpageCourse in Model.Children.Where(x => x.GetPropertyValue("courseListFaculty").Equals("Passfaculty"))){
  

Not sure if Passfaculty is a variable or not!

• You're foraching pageCourse but not using the variable, perhaps you mean something like:

  foreach (var subpageCourse in pageCourse.Children.Where(x => x.GetPropertyValue("courseListFaculty").Equals("Passfaculty"))){
  

A few things to try out :)

Oh I totally missed you putting Passfaculty in a variable, sorry!

My guess of something that may work or perhaps give you a better error message:

@{
    //You may wish to move this @block to the top of the page in time just to keep the markup more clear (eventually into Controller)
    //Changing a few things to make it strongly typed for better debugging
    var passfaculty = CurrentPage.GetPropertyValue<String>("facultyName"); //make sure the current page has a property with alias "facultyName"

    var home = CurrentPage.AncestorOrSelf(1);
    //You may wish to make this search based upon Document Type in time - also check the name of the page below home is exactly "Courselist"
    var courseListPage = home.Single(x => x.Name.Equals("Courselist"));
    //For the next line, make sure that the Children under the courseListPage have a property with the property alias of "courseListFaculty"
    var coursePages = courseListPage.Children.Select(x => x.GetPropertyValue<String>("courseListFaculty").Equals(passFaculty));
}        

<select class="form-control" id="CourseCodeSelect">
    <option selected="selected" value="0">Choose a Course</option>
    @foreach (var coursePage in coursePages){
        var schoolcode = coursePage.GetPropertyValue<String>("courseListSchoolCode"); //is this a string or int? I'm guessing String! - also make sure the course page has a property with alias "courseListSchoolCode"
        <option value="@schoolcode">@coursePage.Name</option>
    }
</select>

I may have made a few typos as all is done in this markdown editor, but give that a go and see if a better error message pops up! :)

It seems like I assumed wrong about "courseListFaculty" being a String in the line:

var coursePages = courseListPage.Children.Select(x => x.GetPropertyValue<String>("courseListFaculty").Equals(passFaculty));

Just a random guess here since I'm not 100% inside your solution, but maybe:

var coursePages = courseListPage.Children.Select(x => x.Name.Equals(passFaculty));

instead would do? Or perhaps something similar? This isn't very pretty, but perhaps it would work untill refactored?

Yeah that doesnt seem to work either :-( the facultyName is on the courselist repository and and also on the faculty pages of the site so what i am trying to do is say for instance the faculty "A Level" on the A Level page and that drop down would only show the A Level courses from the CourseList Repository it does work as shown below but each time a new faculy gets added i need to go add a new one for the marketing team :-(

@if (faculty == "A Level"){
        foreach (var pageCourse in @Model.Content.AncestorOrSelf(1).Children.Where(x => x.Name == "Courselist")){
         foreach (var subpageCourse in pageCourse.Children.Where("courseListFaculty == \"A Level\"")){
          var content = Umbraco.TypedContent(@subpageCourse.Id);
          var schoolcode = content.GetPropertyValue("courseListSchoolCode");
          <option value="@schoolcode">@subpageCourse.Name</option>
         }
        }
       }
       else if (faculty == "Accountancy"){
        foreach (var pageCourse in @Model.Content.AncestorOrSelf(1).Children.Where(x => x.Name == "Courselist")){
         foreach (var subpageCourse in pageCourse.Children.Where("courseListFaculty == \"Accountancy\"")){
          var content = Umbraco.TypedContent(@subpageCourse.Id);
          var schoolcode = content.GetPropertyValue("courseListSchoolCode");
          <option value="@schoolcode">@subpageCourse.Name</option>
         }
        }
       }
      else if (faculty == "Marketing"){
       foreach (var pageCourse in @Model.Content.AncestorOrSelf(1).Children.Where(x => x.Name == "Courselist")){
        foreach (var subpageCourse in pageCourse.Children.Where("courseListFaculty == \"Marketing\"")){
         var content = Umbraco.TypedContent(@subpageCourse.Id);
         var schoolcode = content.GetPropertyValue("courseListSchoolCode");
         <option value="@schoolcode">@subpageCourse.Name</option>
        }
       }
      }
     else if (faculty == "Leadership and Management"){
       foreach (var pageCourse in @Model.Content.AncestorOrSelf(1).Children.Where(x => x.Name == "Courselist")){
        foreach (var subpageCourse in pageCourse.Children.Where("courseListFaculty == \"Leadership and Management\"")){
         var content = Umbraco.TypedContent(@subpageCourse.Id);
         var schoolcode = content.GetPropertyValue("courseListSchoolCode");
         <option value="@schoolcode">@subpageCourse.Name</option>
        }
       }
      }
    else if (faculty == "Procurement and Supply"){
       foreach (var pageCourse in @Model.Content.AncestorOrSelf(1).Children.Where(x => x.Name == "Courselist")){
        foreach (var subpageCourse in pageCourse.Children.Where("courseListFaculty == \"Procurement and Supply\"")){
         var content = Umbraco.TypedContent(@subpageCourse.Id);
         var schoolcode = content.GetPropertyValue("courseListSchoolCode");
         <option value="@schoolcode">@subpageCourse.Name</option>
        }
       }
      }    
      else if (faculty == "GCSE and IGCSE"){
       foreach (var pageCourse in @Model.Content.AncestorOrSelf(1).Children.Where(x => x.Name == "Courselist")){
        foreach (var subpageCourse in pageCourse.Children.Where("courseListFaculty == \"GCSE and IGCSE\"")){
         var content = Umbraco.TypedContent(@subpageCourse.Id);
         var schoolcode = content.GetPropertyValue("courseListSchoolCode");
         <option value="@schoolcode">@subpageCourse.Name</option>
        }
       }
      }
      else if (faculty == "Learning and Development"){
       foreach (var pageCourse in @Model.Content.AncestorOrSelf(1).Children.Where(x => x.Name == "Courselist")){
        foreach (var subpageCourse in pageCourse.Children.Where("courseListFaculty == \"Learning and Development\"")){
         var content = Umbraco.TypedContent(@subpageCourse.Id);
         var schoolcode = content.GetPropertyValue("courseListSchoolCode");
         <option value="@schoolcode">@subpageCourse.Name</option>
        }
       }
      }
      else if (faculty == "Human Resources"){
       foreach (var pageCourse in @Model.Content.AncestorOrSelf(1).Children.Where(x => x.Name == "Courselist")){
        foreach (var subpageCourse in pageCourse.Children.Where("courseListFaculty == \"Human Resources\"")){
         var content = Umbraco.TypedContent(@subpageCourse.Id);
         var schoolcode = content.GetPropertyValue("courseListSchoolCode");
         <option value="@schoolcode">@subpageCourse.Name</option>
        }
       }
      }

Thanks

Aha, I'm not quite sure about these data types, but perhaps in your first post, you could just change the:

foreach (var subpageCourse in Model.Children.Where("courseListFaculty = @0", "@Passfaculty")){

to

foreach (var subpageCourse in Model.Children.Where("courseListFaculty = @0", Passfaculty)){

?

I now have a new error :-(

What if you instead do:

pageCourse.AsDynamic().Children

in the line of the error?

No worries! Just be sure to refactor it at some point, future you will thank you endlessly! :)

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