There are two bugs.
The first is that the Hearthstone mercenaries mode is unable to be opened. Simple as that. If you have a Chromebook mercenaries does not work.
The second is an old bug that was never fixed. We are unable to chat with anyone in game. Keyboard interface from Chromebook does not merge with Hearthstone. So no types of sentence or phrase is able to be sent. The enter key does not send.
waiting on the first bug to be fixed still. starting to get pissed off. -_- customer service told me they were working on it but you can’t really believe anything they say. I’ve tried from a chromebook and my phone but can’t get through to the mode on either one. I get the little video with valeera and then I click Let’s Go then get an error message… “Unable to load this menu. Please try again”
This is pretty stupid 
I was hoping what solved the mercs for me would work for you!
I am now able to play on my chromebook - since I started the tut on my phone and then came back to the book to play it.
The chat issue I just don’t even bother trying any more
:’( i may try from my neighbor’s computer later to see if I can get through it but the button to get in may not work on it either. my phone wouldn’t load it either.
I was able to play on my phone and get through the tutorial. Once I completed the tutorial is able to log back in and play on my tablet/ Chromebook. Try that out and see if that works for you guys as a temporary fix. I can now play on my Chromebook I just had to get past the tutorial on a different platform.
yeah thats what i did. used a friend’s laptop to do the tutorial… works on my chromebook now.