Sigma reported AF issues when using their lenses with the Nikon D5300 camera. A new firmware update to address those problems will be released tomorrow. If your Sigma lens is not compatible with the USB dock, you will have to contact your nearest Sigma service center in order to get the update.
Information Regarding the Nikon D5300 Cameras
Thank you very much for purchasing and using Sigma products. We have found that the current firmware of our Nikon fitting interchangeable lenses may not work properly with the Nikon D5300’s OS and Live View Auto Focus functions. For those customers who own Sigma lenses in Nikon mount, we are going to provide a free firmware update service. Please note that all the products we dispatch from the factory will have the latest firmware.
Without the latest firmware, the OS and Live View Auto Focus functions do not work properly when it is used with the Nikon D5300.
Nikon fitting interchangeable lenses that incorporate an internal motor.
* Firmware upgrade cannot be applied to the lenses that do not have an internal motor.
* For some discontinued products, we may not be able to offer the firmware update due to the discontinuation of related repair parts. Please contact your nearest authorized Sigma distributor for the further details.
For those customers in need of the latest firmware, we are going to provide free firmware update from November 20th. For discontinued products, please contact your nearest authorized Sigma distributor for the further details. For lenses that are compatible with the SIGMA USB DOCK, it is possible to update them via SIGMA Optimization Pro.
Update: the firmware update can be downloaded here.