In the not too distant future, the default for continuation for API action=query will be changing from the current "raw" format to a more user-friendly format, see here for the most recent announcement of this planned change.
This extension appears to be using query-continue, and so will probably be affected by this change. If you wish to continue using the "raw" format, specify the 'rawcontinue' parameter in your API queries. To be ready for the new format (documented here), specify the 'continue' parameter with the empty string as a value in the initial query.