Laravel-datatables: datatables warning ajax error 404 not found

Summary of problem or feature request

I am new to laravel. I was able to run datatable using jquery plugin.
I would like the server side processing. I encountered error 404 the other day. Today I encountered
500 Internal Server Error. Call to undefined method Yajra\Datatables\Datatables:

• Call to undefined method Yajra\Datatables\Datatables::eloquent() is present. Yesterday it was 404 file not found. Please help me fix error so that I can run server side processing. I am unable to see what causes this. Could it be that I am using sorting and search in my index?
• I also tried to check the demo regarding left join however was unable to get the demo.
  An accession has categories and so need a join. **_How do you output data that comes from a join
  in the columns? Can you provide simple example for join used in server side processing?
• How about if you also need a view and edit button in the columns, how do you place them?

Thank you for looking at this.

Code snippet of problem

here is route..

index.blade.php

service provider

alias

then accession

public function index(Request $request){

    $categories = Category::all();

    $query = Accession::select('*');

    //this is for links that will run query according to
    //category type

    if ($request->input('type')){

        switch ($request->input('type')){

            case 'Photo':

                $query->where('category_id', 2);

                break;

            case 'Field Notes':

                $query->where('category_id', 3);

                break;

            case 'Audio Recording':

                $query->where('category_id', 4);

                break;

            case 'Instrument':

                $query->where('category_id', 5);

                break;

            case 'Music Scores':

                $query->where('category_id', 6);

                break;

            case 'Video':


                $query->where('category_id', 7);

                break;

            case 'Vertical Files':

                $query->where('category_id', 8);

                break;

            default:

                $query->orderBy('id', 'asc')->get();
        }

        $accessions = $query->orderBy('id')->get();
        return view('accessions.index', compact('accessions', 'categories'));


    }

    //this is for search bar

    $search = $request->input('search'); //<-- we use global request to get the param of URI

    if($search){

        $accessions = Accession::where('groupcountry','LIKE','%'.$search.'%')
                    ->orWhere('description', 'LIKE', '%'.$search.'%')
                    ->orWhere('author', 'LIKE', '%'.$search.'%')
                    ->orWhere('accession_no','LIKE','%'.$search.'%')
                    ->orWhere('year','LIKE','%'.$search.'%')
                    ->paginate(10);

        return view('accessions.index', compact('accessions', 'categories'));
    }
    else{


        $accessions = Accession::orderBy('id', 'asc')->get();
        return view('accessions.index', compact('accessions', 'categories'));
    }


}

System details

• Operating System Windows 10
• PHP Version PHP 5.6.20
• Laravel Version Laravel Framework version 5.2.45
• Laravel-Datatables Version 6.0