Messaging not default SMS app

[sehnsucht]

Every few days I get a notification:

"Messaging not default sms app. Tap to make Messaging your default SMS.."

(that's what it says; it actually stops mid sentence). I click on it and there's a dialog box:

"Change SMS app?
Use messaging instead of Hangouts as your SMS app?
No Yes"

Now obviously I don't want to do this (why would anyone), but I click on No and the box goes away but it'll come back again later. I can't uninstall messaging, and when I load it to see if it has options to never do anything again ever the first thing it does is pop up the "Change sms app" box again, and when I press No it quits.

Hangouts is indeed my default SMS app; it's enabled (you can see it in the settings), it works (i receive SMS and hangout messages through it).

Do I have to start disabling apps, or is there a way of getting this to stop? I'm on 5.0.2 on a 6603 (uk unbranded) and this problem is new to lollipop.

[Rickard]

Could you test if the same thing happens in safe mode? It could perhaps be another app that's triggering our messaging app which will then give this question.

But as you say, one solution is to disable "Messaging" under Settings -> Apps -> All.

[sehnsucht]

It happens every  3-5 days. Not sure I can leave my phone in safe mode for that long; I might have to just disable it!

[Rickard]

I can understand that, with safe mode you will not have access to any downloaded apps.

But as you want to use Hangouts and not Messaging i can't see any reason to not disable Messaging. In case you want to use it some day, just enable it again.