kintone.com was updated during the scheduled maintenance on Friday, February 10th, 2017 (Pacific). We had a few API bug fixes in this update.

• Fixed a bug where field error messages would not appear, when a value was placed in the error property of attachment fields.
  This occurred on the record list, for the following events:
  • app.record.index.edit.submit
  • app.record.index.edit.change.(fieldcode)
• Fixed a bug where errors would occur when the disabled property of Text (single-line) fields were set to false.
  This occurred on the record list, when the Text (single-line) field option was set to "Calculate automatically", for the following events:
  • app.record.index.edit.show
  • app.record.index.edit.change.(fieldcode)

• Fixed a bug where specifying null for the revisions parameter would state that you sent an Illegal request, when using the Delete Records API . Now doing the same thing won't give you any errors, and the specified records will be deleted.

• Not exactly an API related update, but the February update introduced a new Webhook feature. You can check up on how to set up a Webhook for your Kintone app here .