Invalid MMI Codes error

[xznewbie]

Hello guys, Have anybody encountered this Invalid MMI code error in your Sony Xperia dual SIM..?
How did you resolve it..?

[Jonas]

Thanks for the update and I'm happy to hear that has been some improvement!

I hope they will resolve this as soon as possible as well, it's never fun to have error messages and not being able to use certain basic functions in the phone.

Keep me posted and have a great Friday and a great weekend!

[xznewbie]

Update of the this thread... I contacted the service provider and have the SIM card replaced but the fault is still there.they have done many things just to find solution.The fault remains.
Now this lead me to ask questions.Is this fault exclusive to dual sim xz. As this happens with the secondary Sim and never with the primary ones.. Have anyone has an experience in interchanging the SIM card, like Sim card 1 goes to sim card two slot and conversely. . What was the result? Will doing such interchange not screw up the phone software..?
Another question,, is regular swapping of LTE to WALMART between the two Sim card due different signal strength will not gradually impair the SIM or its contact points as well as the phone software for this particular application. What I mean will it not cause permanent damage. I was asking this s as when this xz phone was new and freshly installed with two Sim card, I did not experience this error. Only after a more than a month of regular juggling the function, like call, text and data between the two Sim card did this "connection problem or invalid MMI code arise.

[xznewbie]

Gosh this SwiftKey is problematic. The statement I meant was LTE to WCDMA.. between the two Sim cards.

[Jonas]

Hi again!

I am so sorry for the late reply.

It's hard to say what isn't working as it should, the error message is a network error at least.

I checked with a few colleagues of mine that are using Xperia XZ Dual and they haven't experienced the same behaviour and they are switching quite a lot between which card should be used for calling, sending text messages and so forth. This is something that is completely normal for users to do so it should not harm the software in any way.

To be able to rule out that it's caused by your service provider I'd recommend trying 1 or 2 SIM cards from a different operator in your phone, if you can borrow 1 or 2 from a friend and test in your phone. You can also contact your service provider and see if they are able to reset the subscription on both your SIM cards back to default.

Once again, I am sorry for the late reply and for the time it's taking to sort this out.

Keep me posted and have a great weekend!