title: Blob Data error when fetching react-native
body: <p>I am using react native to make a chat-like app. Postman is working properly while doing all the requests I made possible in .NET core api. But when I am trying to fetch from react native it gives the following error:</p>
  
  <p>"null is not an object (evaluating 'blob.data')"</p>
  
  <p>I have tried to look into this issue in different articles but haven't found anything</p>
  
  <pre><code>return new Promise((resolve, reject) =&gt; {
              fetch('https://localhost:44305/api/replies', {
                  method: 'POST',
                  headers: {
                      Accept: 'application/json',
                      'Content-Type': 'application/json',
                  },
                  body: JSON.stringify(qId)
              })
                  .then(res =&gt; res.json())
                  .then(result =&gt; resolve(result))
                  .catch(err =&gt; reject(err))
          })
  </code></pre>
  
  <p>I am trying to get a list of answers to a question. Doing it from Postman works fine. I can't find a solution for this error.</p>
  
  <p>I have tried adding return, just like somebody mentioned in a comment before fetch. The result is the same..</p>
  
  <p>Thank you in advance!</p>
  
  <p><a href="https://i.stack.imgur.com/gppFJ.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/gppFJ.png" alt="enter image description here"></a></p>