Update the Ultimaker 3 firmware
Periodically, a new version of the Ultimaker 3 firmware is released. To ensure that your Ultimaker 3 has the latest features, we recommend keeping the firmware updated. This can be performed on the Ultimaker 3 when connected to a network.

Update your Ultimaker 3 via the network
Before you can update to the latest firmware, you must install an intermediate firmware version (4.3.97). When installing firmware over the network, the correct installation order is determined automatically.

Connect the printer to the network via Wi-Fi or Ethernet in the SYSTEM > Network menu if you haven¡¯t already.
Go to SYSTEM > Maintenance > Update firmware
Select the stable version.
The Ultimaker 3 will download the firmware from the server and install it automatically. This may take several minutes.
Navigate to the update menu again.
Select stable again, which will install version 5.2.11
Update your Ultimaker 3 via USB
Firmware can also be updated without an active network connection.

You must first install an intermediate firmware version (4.3.97). Follow the steps below to update your printer:  

Download firmware 4.3.97 file 1 and file 2 (.tar.xz and .tar.xz.sig)
Place both files on the USB stick in the root directory.
Insert the USB stick into your printer's USB port.
Go to SYSTEM > Maintenance > Update firmware and select 4.3.97 in the update menu.
Wait for the Ultimaker 3 to finish updating the firmware.
The intermediate firmware is installed.

To update to the stable version, follow these steps:

Download the latest firmware. This time you only need one file (.swu)

Place the file on the USB stick in the root directory.
Insert the USB stick into your printer's USB port.
Go to SYSTEM > Maintenance > Update firmware, and select the new firmware in the update menu.