[2017-01-26 18:11:43,546: VERBOSE/PoolWorker-1] Caught HTTP 504 error; retrying
[2017-01-26 18:11:43,546: WARNING/PoolWorker-1] Waiting 5 seconds before retrying.
[2017-01-26 18:11:48,553: VERBOSE/PoolWorker-1] Submitting unthrottled action 'upload'.
[2017-01-26 18:11:52,902: WARNING/PoolWorker-1] API error stashfailed: Invalid chunk offset
[2017-01-26 18:11:52,903: VERBOSE/PoolWorker-1] API Error: query=
u"{u'ignorewarnings': [False], u'maxlag': ['5'], u'format': [u'json'], u'filekey': [u'14mmy2n4vmdc.ufzbjk.234501.webm'], u'stash': [True], u'filename': [u'Za Slovenijo brez zavr\\u017eene hrane - kako naprej.webm'], u'assert': [u'user'], u'token': [u'REDACTED'], u'filesize': [1568259475], u'offset': [385875967], u'action': [u'upload'], u'async': [True]}"
[2017-01-26 18:11:52,903: VERBOSE/PoolWorker-1] response=
{u'servedby': u'mw1290', u'error': {u'info': u'Invalid chunk offset', u'code': u'stashfailed', u'help': u'See https://commons.wikimedia.org/w/api.php for API usage.', u'offset': u'402653183'}}Since offset is given back, ideally pywikibot can correct its own offset variable and continue with the upload.