Steps to reproduce:

  1. Perform a fresh install of the latest Drupal 8.x (I'm on 6bcbd0ae)
  2. Verify that upload on an image field works correctly without changing the cardinality:
    1. Click "Add new content"
    2. Click "Article"
    3. Under "Image" click "Choose file", find a small image (png, gif, jpg, jpeg) and click "Upload"
    4. The image thumbnail should appear - so image uploading is working!
  3. Now, navigate to this path on your site: admin/structure/types/manage/article/fields/field_image/field-settings
  4. Change the "Maximum number of values you can enter" to "Unlimited"
  5. Navigate back to the article create form: node/add/article
  6. Under "Image" click "Choose file", use the same images as before and click "Upload"
  7. The AJAX spinner will appear, go away and the thumbnail WILL NOT appear and the image WILL NOT be uploaded

Strangely, after using the site for a while and adding/removing other fields, this will sometimes start working later. Unfortunately, I haven't been able to recreate the steps required for it to start working.

Comments

dsnopek’s picture

dsnopek
he/him
Primary language English
Location USA
CreditAttribution: dsnopek commented

I kept messing around trying to see what would cause it to start working. The last thing I tried was clearing the cache but I'm not 100% sure this is what did it.

dsnopek’s picture

dsnopek
he/him
Primary language English
Location USA
CreditAttribution: dsnopek commented

Gah, apparently, it still doesn't work sometimes. I really don't know why it fails or succeeds...

swentel’s picture

swentel CreditAttribution: swentel commented
Status: Active » Closed (cannot reproduce)

Can't reproduce this on HEAD currently, lot's of fixes have been in the meantime, so I think we're safe. In case you see this happening, try looking into the error.log and see if anything is in there.