Steps:
1. Go to Admin panel and create new content type.
2. Fill the form with:

Content type name: ImageTest
Content type identifier: imagetest
Content name pattern: <title>

3. Add three field types: image, image, textline
4. Change nothing in first image field
5. Fill the second image fields, for ex:

name: image
identifier: image

5. Fill text line fields, for ex:

name: Title
identifier: title

6. Click "OK"
7. Go to "Create" and choose content type added before - there is error 500