Kintone will be updated on the midnight of September 11th (Pacific time).
Some API bugs will be fixed on this update.

Kintone REST API

Bug fixes

• The error stated "Illegal request." when the Get Records API had a query that was too long.
  After this update, the error will state "Too many filter conditions are specified. Reduce the number of filter conditions.".
• The error stated "Illegal request" for lock timeouts.
  After this update, the error will return more detailed reasons instead.
• Duplicate values for categories could be selected using JavaScript APIs.