Thumbnail doesn't appear when an image is first uploaded and added in Content then chosen as Thumbnail, image doesn't appear in Content after Save & View also

Steps to reproduce:

1. Log in as Admin
2. Add a title to create a new blog post
3. In the Content add some text and an Image through Upload (Browse > Send it to Server > OK)
4. Type some text in Summary
5. Click on Choose an image
6. Select the image uploaded above
7. Select a category
8. Publish the article
9. Click Save & View

Expected results: The image shows in Content and as Thumbnail.

Actual results: The image doesn't show in Content or in Thumbnail after Save & View. In Content only the name appears and if you Edit the blog post again and go to Choose an image for the Thumbnail you will see the image doesn't appear there anymore.