The Unable to Complete Cellular Plan Change error message is related to an installation failure which can be caused by different factors as follows:

1. Too many eSIMs are installed on the device. eSIM-compatible devices allow you to install multiple eSIMs, but depending on the device model, the number of eSIMs you can have active simultaneously may vary. For example, iPhones can store 5 to 10 eSIMs, depending on the device's storage. For more information, please contact your phone manufacturer.

•  If you confirm that you have maximized your device's eSIM storage. You can remove your old eSIMs on the device. You may see the instructions on how to remove eSIMs here: How can I remove an eSIM from my device?

2. Cellular/Mobile data is disabled in the device's settings 
   
   
3. Trying to install an eSIM that was already installed: most eSIMs can only be installed once.

• You can verify if the eSIM is installed on your device by Going to Settings > General> About> Scroll down to find the ICCID (it's a 20-digit number that starts with 89XXXXXXXXXXXXXXXXXX and ends with a random extra number). If you confirm that the ICCID has been installed it might be a matter of making a few adjustments to get connected. Please refer to your eSIM installation page for all the details.

4. Poor connection when trying to install the eSIM. This commonly happens when using the ship's wi-fi or public wi-fi. If the issue persists, please contact support.