On my Xperia Z1 compact and cm 12 I used the Dark Material theme. Then after a recent update it was disabled 'after too many app crashes'. I tried to set it again but now every time I go to settings->themes it exits with the error 'unfortunately, settings has stopped'.
Some posts on the web suggest that in settings->apps, clearing the data for the Theme Chooser app (under All Apps) will solve it. But there is no Theme Chooser app in my app list.
Is it possible to (re)install Theme Chooser somehow? Or another way to be able to switch Themes in cm 12?
phone: Sony Xperia Z1 compact (amami)
OS: cm 12.1 update 20160110
android: 5.1.1
EDIT
I tried (re)installing the Themes APK generously provided by the author of this post, but when I open the APK it first says "Do you want to install an update to this built-in application? Your existing data will not be lost. The updated application will get access to New|All", and when I choose either of those it exits with "App not installed."
That means that Theme Chooser is still on the phone. But why does it then not appear in the "All Apps" list (which would allow me to Clear Data)?
EDIT II
I dirty flashed the latest image (15/1) from the cyanogedmod website. Still no theme chooser that works.