https://community.sony.lt/t5/xperia-archive/could-not-switch-calls-is-the-error-message/m-p/3328234#M451575 It is a network issue. Contact them again and ask them to check your phone. Since the Xperia Z3 is capable of that. Also you may also just need to get a new sim card. Thu, 25 Dec 2014 07:44:27 GMT Phy 2014-12-25T07:44:27Z https://community.sony.lt/t5/xperia-archive/could-not-switch-calls-is-the-error-message/m-p/3328232#M451573 <P>Hi</P><P>When I try to add a second call "could not switch calls" is the error message that always appears.I checked the status with my network provider and my call conference service is active from their side.Please help to solve this issue</P> Thu, 25 Dec 2014 07:29:33 GMT https://community.sony.lt/t5/xperia-archive/could-not-switch-calls-is-the-error-message/m-p/3328232#M451573 dvs5613 2014-12-25T07:29:33Z https://community.sony.lt/t5/xperia-archive/could-not-switch-calls-is-the-error-message/m-p/3328233#M451574 Is your phone locked to a carrier / network branded? How old is your SIM card? Thu, 25 Dec 2014 07:44:06 GMT https://community.sony.lt/t5/xperia-archive/could-not-switch-calls-is-the-error-message/m-p/3328233#M451574 Uliwooly 2014-12-25T07:44:06Z https://community.sony.lt/t5/xperia-archive/could-not-switch-calls-is-the-error-message/m-p/3328234#M451575 It is a network issue. Contact them again and ask them to check your phone. Since the Xperia Z3 is capable of that. Also you may also just need to get a new sim card. Thu, 25 Dec 2014 07:44:27 GMT https://community.sony.lt/t5/xperia-archive/could-not-switch-calls-is-the-error-message/m-p/3328234#M451575 Phy 2014-12-25T07:44:27Z https://community.sony.lt/t5/xperia-archive/could-not-switch-calls-is-the-error-message/m-p/3328235#M451576 <P>ya may be mine is very old sim..thank you</P> Thu, 25 Dec 2014 07:59:41 GMT https://community.sony.lt/t5/xperia-archive/could-not-switch-calls-is-the-error-message/m-p/3328235#M451576 dvs5613 2014-12-25T07:59:41Z