Having troubles posting form data with ajax to controller action (laravel)

Route:

Route::post('admin/cms/create','CmsController@createmenu');

Controller's action:

public function createmenu(Request $request){
        $menu = new menu;
        $this->validate($request,[
            'name'=>'required',
            's_title'=>'required_if:s_exist,1',
            's_desc'=>'required_if:s_exist,1',
            's_path'=>'required_if:s_exist,1',
            'category'=>'required'
        ]);
        $path=$request->file('s_path')->store('img/slideshow');
        $menu::create([
            'name'=>$request->name,
            's_exist'=>$request->s_exist,
            's_title'=>$request->s_title,
            's_desc'=>$request->s_desc,
            's_path'=>$path,
            'category'=>$request->category
        ]);
        return redirect('admin/cms');
    }

Ajax (jquery):

$("#f_ins_menu").on("submit",function(e){
    e.preventDefault();
    var data={};
    $.ajax({
        type:"POST",
        //url:$(this).attr("action"), //I would like it to work with this dynamic url
        url:"cms/create", //this file is inside the folder admin
        //I also tried without the map function
        data:$(this).serializeArray().map(function(x){data[x.name] = x.value;}),
        contentType:false,
        cache:false,
        processData:false,
    });
});

The createmenu action works without the ajax

I have another action that uses Ajax and it works, but the difference is: in that action I don't pass Request $request, in fact I don't pass anything.

I have tried in native PHP and it works. Note that I added contentType:false, cache:false, processData:false, because I also pass a file.

I have tried to die and dumb (dd) the $request param and I get a huge block of code, I think a class, so my thoughts are that Request $request param doesn't get the data I pass through ajax

And yes I have included CSRF_FIELD with the meta tag trick that I found here https://laravel.com/docs/5.4/csrf

Can someone help me with at least seeing the data that I pass is array format or json format, doesn't matter.

I don't want you guys to go over all that code. Can you give me the correct version of this function/action.

public function createmenu(Request $request){
    return dd($request); //I've tried this but it returns alot of code in console.log when I do the success:function()
}

I just want to see the data that I pass, at least, I can go from there.

EDIT:

Forgot to mention that with the validate method the HTTP response is 422 and without the validation the HTTP response is 500

via Cr1xus