[mangadex][error] An unexpected error occurred: KeyError - 'data'

[fsktom]

Hi. I got the following error when trying to download chapters from MangaDex

$ gallery-dl -v https://mangadex.org/chapter/6c2e552c-32b3-4c08-9fd8-ddd5a97d0d7a

[gallery-dl][debug] Version 1.20.0
[gallery-dl][debug] Python 3.9.5 - Windows-10-10.0.19043-SP0
[gallery-dl][debug] requests 2.25.1 - urllib3 1.26.6
[gallery-dl][debug] Starting DownloadJob for 'https://mangadex.org/chapter/6c2e552c-32b3-4c08-9fd8-ddd5a97d0d7a'
[mangadex][debug] Using MangadexChapterExtractor for 'https://mangadex.org/chapter/6c2e552c-32b3-4c08-9fd8-ddd5a97d0d7a'
[urllib3.connectionpool][debug] Starting new HTTPS connection (1): api.mangadex.org:443
[urllib3.connectionpool][debug] https://api.mangadex.org:443 "GET /chapter/6c2e552c-32b3-4c08-9fd8-ddd5a97d0d7a?includes%5B%5D=scanlation_group HTTP/1.1" 200 790
[urllib3.connectionpool][debug] https://api.mangadex.org:443 "GET /manga/e78a489b-6632-4d61-b00b-5206f5b8b22b?includes%5B%5D=artist&includes%5B%5D=author HTTP/1.1" 200 3090
[mangadex][error] An unexpected error occurred: KeyError - 'data'. Please run gallery-dl again with the --verbose flag, copy its output and report this issue on https://github.com/mikf/gallery-dl/issues .
[mangadex][debug]
Traceback (most recent call last):
  File "d:\software\miniconda\lib\site-packages\gallery_dl\extractor\mangadex.py", line 110, in items
    chapter, data = self._cache.pop(self.uuid)
KeyError: '6c2e552c-32b3-4c08-9fd8-ddd5a97d0d7a'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "d:\software\miniconda\lib\site-packages\gallery_dl\job.py", line 79, in run
    for msg in extractor:
  File "d:\software\miniconda\lib\site-packages\gallery_dl\extractor\mangadex.py", line 113, in items
    data = self._transform(chapter)
  File "d:\software\miniconda\lib\site-packages\gallery_dl\extractor\mangadex.py", line 75, in _transform
    "count"   : len(cattributes["data"]),
KeyError: 'data'

This error seems to occur to me for every chapter of every manga. Tested it on 10+ titles, and on none of them did the extraction work.
I looked at the titles of the commits after the last update, and it doesn't seem like this was addressed. Maybe I missed something. Or possibly it's just an error on my machine?
Ask me if you need any more help/details. I would be very glad and thankful if you were able to fix this bug(?).

[L1ckMyP4w5]

Started getting the same error just this morning. Mangadex api most likely changed as I was downloading stuff fine this past january 6th with the same gallery-dl version (1.20.0).
Here's the error dump. I'm on mac osx.

[gallery-dl][debug] Version 1.20.0
[gallery-dl][debug] Python 3.7.6 - Darwin-19.6.0-x86_64-i386-64bit
[gallery-dl][debug] requests 2.26.0 - urllib3 1.26.7
[gallery-dl][debug] Starting DownloadJob for 'https://mangadex.org/title/3cb067f8-d042-4fa0-bd83-86ca7a4e04e8/yuri-to-hitsugi'
[mangadex][debug] Using MangadexMangaExtractor for 'https://mangadex.org/title/3cb067f8-d042-4fa0-bd83-86ca7a4e04e8/yuri-to-hitsugi'
[urllib3.connectionpool][debug] Starting new HTTPS connection (1): api.mangadex.org:443
[urllib3.connectionpool][debug] https://api.mangadex.org:443 "GET /manga/3cb067f8-d042-4fa0-bd83-86ca7a4e04e8/feed?order%5Bvolume%5D=asc&order%5Bchapter%5D=asc&contentRating%5B%5D=safe&contentRating%5B%5D=suggestive&contentRating%5B%5D=erotica&contentRating%5B%5D=pornographic&includes%5B%5D=scanlation_group&offset=0 HTTP/1.1" 200 None
[urllib3.connectionpool][debug] https://api.mangadex.org:443 "GET /manga/3cb067f8-d042-4fa0-bd83-86ca7a4e04e8?includes%5B%5D=artist&includes%5B%5D=author HTTP/1.1" 200 891
[mangadex][error] An unexpected error occurred: KeyError - 'data'. Please run gallery-dl again with the --verbose flag, copy its output and report this issue on https://github.com/mikf/gallery-dl/issues .
[mangadex][debug]
Traceback (most recent call last):
File "/usr/local/lib/python3.7/site-packages/gallery_dl/job.py", line 79, in run
for msg in extractor:
File "/usr/local/lib/python3.7/site-packages/gallery_dl/extractor/mangadex.py", line 41, in items
data = self._transform(chapter)
File "/usr/local/lib/python3.7/site-packages/gallery_dl/extractor/mangadex.py", line 75, in _transform
"count" : len(cattributes["data"]),
KeyError: 'data'

[fsktom]

Thank you so much for the very fast fix @mikf ! :D