I didn’t even know it was possible to upgrade this way. But since there were some major updates between version 1.1 and 1.2 I would assume, that there are more files involved.
So the way it’s supposed to work is to call ionic lib update. Yet this somehow didn’t work for me. It would always jump back to 1.1 (can be checked via ionic lib -v.
What I ended up doing is modify the bower.json from
"ionic": "driftyco/ionic-bower#1.2.1"
to
"ionic": "driftyco/ionic-bower#1.2.1-nightly-1867"
as recommended here: Anyone else having problems with 1.2.1?
and then calling ionic lib update would work.
Not sure if that’ll solve your problem. You can also debug your build and see if there’s any file missing.