"Speech recognition is not supported on this machine".

I'm trying out unity's built in speech recognition API, but I'm only getting this error message:

UnityException: Speech recognition is not supported on this machine. UnityEngine.Windows.Speech.DictationRecognizer..ctor (ConfidenceLevel minimumConfidence, DictationTopicConstraint topic) (at C:/buildslave/unity/build/Runtime/Export/Windows/Speech.cs:316) UnityEngine.Windows.Speech.DictationRecognizer..ctor () (at C:/buildslave/unity/build/Runtime/Export/Windows/Speech.cs:300) Recognizer.Start () (at Assets/Scripts/Recognizer.cs:20)

I was trying it out with unity's own sample code:

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 using UnityEngine.UI;
 using UnityEngine.Windows.Speech;
 
 public class Recognizer : MonoBehaviour {
 
     [SerializeField]
     private Text hypotheses;
 
     [SerializeField]
     private Text recognitions;
 
     DictationRecognizer dictationRecognizer;
 
     // Use this for initialization
     void Start()
     {
         dictationRecognizer = new DictationRecognizer();
 
         dictationRecognizer.DictationResult += (text, confidence) =>
         {
             Debug.LogFormat("Dictation result: {0}", text);
             recognitions.text += text + "\n";
         };
 
         dictationRecognizer.DictationHypothesis += (text) =>
         {
             Debug.LogFormat("Dictation hypothesis: {0}", text);
             hypotheses.text += text;
         };
 
         dictationRecognizer.DictationComplete += (completionCause) =>
         {
             if (completionCause != DictationCompletionCause.Complete)
                 Debug.LogErrorFormat("Dictation completed unsuccessfully: {0}.", completionCause);
         };
 
         dictationRecognizer.DictationError += (error, hresult) =>
         {
             Debug.LogErrorFormat("Dictation error: {0}; HResult = {1}.", error, hresult);
         };
 
         dictationRecognizer.Start();
     }
     
     // Update is called once per frame
     void Update () {
         
     }
 }
 

I'm using Windows 10, I know the speech recognizer works, I've enabled it, I got the correct langugage package, I can talk with cortana etc. The problem seems to be only in unity. I read somewhere about a microphone setting in player settings under project settings, but there are no microphone settings there. I'm thankful for some help.