Cause:

• The data roaming function may be disabled.
• If you are in arrears, you cannot use data services during roaming.
• The data package may not support the roaming data service.

Solution:

• Check whether the data roaming function is enabled. If not, swipe down from the top of the screen to open the shortcuts panel, touch and hold the Mobile data icon to enter the Mobile network settings screen, and enable Data roaming.
• Check whether you are in arrears. Contact your carrier for details.
• Check whether your data package supports the roaming data service. Contact your carrier for details.