Thread:Project:Support desk/API error: No JSON object could be decoded

I have an error with API using latest pywikipedia. API is turn on in LocalSettings.php and have worked about 6 month ago (but since that I've moved to another server, upgraded wiki from 1.17 to 1.18 and changed permalinks as described here ).

The error is:

Logging in to domainname:ru as USERNAME via API. Error downloading data: No JSON object could be decoded Request ru:/w/api.php Retrying in 1 minutes...

I've checked BOM as described here (http://sourceforge.net/tracker/?func=detail&aid=3019475&group_id=93107&atid=603139) and do not get any errors.

Need advice!