Why does my Moto X Pure crash while updating to Marshmallow?

[AC Question]

I have a Moto X Pure 16 GB (US version), but am using a Singapore SIM card. I got the Marshmallow OTA update notification, but every time I try to install the update, I get an érror' message at the green robot screen.

I've tried a factory reset, removing the SIM card, and the SD card, but nothing works. Would really appreciate some advice as I'm quite excited about upgrade to MM.