Arduino M0 Pro / Zero

What is the problem with the Arduino M0 PRO / ZERO why the two names and why
the confusion over the latest software versions.
I programmed the Zero once now it has locked up with errors. I have been using
UNO's for years with no problems then this spat between Europe and USA seems to
have complicated maters. Its the first genuine Arduino I have bought for a while and
its rubbish, should have gone to Ebay......
Any Idea's how I revive it - no comms on either Port, Power LED on

Rgds, Malc