I have well over 300 Mercenary coins for Murky which is how many is required to craft an Epic Mercenary however the game refuses to let me craft him.
Please can this be fixed, I would like my murloc 
The mercenary mode no longer recieves support and updates.
This is one of the many bugs which happen for many months now and has been reported by a number of players but is unlikely to be fixed in the future.
Ive also been having this problem, and I’ve even deleted and redownload everything and nothing is fixing it. My main problem is I love Murloc’s and was so excited to see that I had enough
They really should fix it. Murky was once a track reward, not craftable card. So people who missed out on the track reward could not get him even though they collected the coins. This should have been fixed months ago but sadly there is no merc support any more.
I had to stop playing the mode because there were no new heroes to unlock and the heroic mode equipment challenges got too hard for me.
The merc support stop is not acceptable as long as they sell mercenaries card pack for real money. But yes seems that this problem has been reported many times since more than one year now.
Gentle reminder for Blizzard. New patch but this bug is still active.
It is impossible to have Murky anymore (and probably chromie too)
An old issue.
Truly? Can’t you get their portraits from packs?
I think I got Chromie’s portrait lately.
And, digging up something old, but…
Truly? You mean heroic, not mythic? I’m not really into the latter, but the former is where the actual fun starts, in my opinion.
You can have murky coins in pack, but the craft animation is bugged and never finish. It is why currently you cannot craft murky.
The question was about portraits, if you haven’t noticed.
I do not know if Murky is available in pack as a portrait. I believe he was a special reward, so i’m afraid that he may not exist as portrait.
Anyway it will not correct the craft bug. If you have coins in pack and the game propose you to craft Murky you should be able to do it.
Once obtainable from the reward track only (the base portrait from the free one, others from the paid), but that time is bygone. I got a bunch of his golden portraits from packs since, thus he should have been obtainable, but I don’t remember in what patch it was, so the question was whether you can get him right now.
Ugh, looks like you don’t understand the basics of how portraits work, but I don’t feel like explaining it right now… unless you ask nicely. 
I believe it’s documented, though.
Which means that Murky might be uncraftable, but not unobtainable.
By the way, epic mercs aren’t usually that hard to get from packs, plenty of which you get for progressing in the game anyway, so crafting them is probably a waste of time, if you ask me. Legendaries, on the other hand, might be… elusive, so that’s a different matter, and I understand if one wouldn’t want to open about 40 packs just to hunt that one missing merc, and crafting could be an option to get it faster.
I wish this would get fixed so bad
If you’re into the mode, you can get a lot of free packs, even if you don’t want to buy any with gold, just by completing task chains for other mercs. Epic mercs shouldn’t be that hard to open that way, and you can even increase the odds to get the one you want by crafting some others of that rarity — assuming Murky is still obtainable from packs (see the question above). That’s the only possible workaround I’d realistically look forward to.