Warning: file_put_contents(temporary://): failed to open stream I get this message from Drupal:

Warning: file_put_contents(temporary://file8vyLsO): failed to open stream: &quot;DrupalTemporaryStreamWrapper::stream_open&quot; call failed in file_unmanaged_save_data() (line 1900 of /home/donatelo/public_html/thenameofthesite.com/includes/file.inc).
The file could not be created.

I don't know what I did to cause this, can anyone help me?
Make sure your temporary folder exists and is writeable.

See the file system settings at:

admin/config/media/file-system