Cannot add image in Web content rich text field in firefox

• Type: Bug
• Status: Closed
• Resolution: No Longer Reproducible
• Affects Version/s: Master
• Fix Version/s: None
• Component/s: CKEditor
• Labels:
  • 7.4-blocker
• Fix Priority: 5
• Browsers:
  Firefox (latest)

Steps to reproduce

1. Add a web content based in Basic Web Content
2. Click ckeditor button to add a image
3. upload an image and add it

Expected result

the image is added

Actual result

**the ckeditor dissapear and an error is displayed