I can't make a call after a software update (Xperia 1)

This article is for Xperia 1 calling issues after a software update. 

Issue

We apologize for any inconvenience.

You might experience that you get an error message when trying to make a call.

Information / Solution

This issue has already been solved.

Please update your Xperia's software to the latest version.

Tips: How to check the latest software.

Find and tap [Settings] → [System] → [Advanced] → Software update.

If the following comment is displayed, it is the latest SW:

"Your device already has the latest available system updates."