I believe there was a similar topic to this recently but couldn't find it using search so my apologies if my issue was answered in that thread.

Recently completed Waking Nightmare so went to see Skaal and he gave me the kill a giant at Blizzard Rock quest
Did that, returned, got paid and he gives me the spiel about helping his people to become a Thane (and I'm already two thirds of the way there)
However the report to Skaal objective doesn't clear and he won't give me another quest
Get another quest from the innkeeper, complete it, report back to Skaal and get paid but don't progress towards becoming a Thane

Any tips on how to resolve this. I'm on PC, not running any mods that should affect this, and have prior saves both before and after Waking Nightmare but would prefer not to have to do it again.

make sure you do atleast 3 quests around town

examples are fetching items for the blacksmith, the captain at the boat and the alchemist

whats your latest journal entry?

I've fetched the book for the blacksmith, the salts for the captain, and handed in a bounty previously. I'll try the alchemists quest and see if that works.

Latest journal entries are:

• Assist the people of the Pale (2/3)
  
• Collect bounty from Skald

but the bounty is one I've already been paid for and hasn't cleared

Also, Anga's Mill (near Windhlem). She gives you a message to give to Skald and that can satisfy the Thane requirement.

That one will never go away. In fact, if you do other bounty quests for him you will have multiples of that entry.

I have never been able to complete the Waking Nightmare quest. Every play thru the guy disappears when entering the ruins.

But I still became thane. The book, the delivery ... can't remember when else I did.

He did this on my 2nd playthrough, but I knew what caused it. A Frost Troll or two ran up the hill/mountain and attacked while I was in the dialogue with him outside. When I reloaded, killed the Trolls, and then spoke with him it proceeded normally. I guess your issue isn't that simple.

This. There's also no way to clear it via console or anything so it just sits there, taunting you.

But yeah, as was recommended, head down to Anga's Mill and speak to the owner lady and ferry her message over to Skald. I was struggling to get the right amount of favors done, too, and that helped me. Other options you got are find Fine Cut Void Salts for the captain guy, get a book for the blacksmith, and find a ring for the alchemist.

As suggested 1 extra favour did it. Thanks all
Seems bounties don't count as helping people in the Pale.
Also Skald seems to have something against giants. Besides the kill the giant quest I've also done 2 bounties for him that were both giants

Anyway once I find a bottle of Black Briar Mead Griselda will be Thane of all the Holds. Griselda refuses to buy one for that freeloader in Falkreath

I wonder what that could mean.

Nope. After multiple reloads and most anything I could find in the wikis, I gave up. If the guy wants to hide inside of his place, and the dialogues in town stop, then fine, whatever.

Erandur's had a bad history of not pathing correctly, he either walks through walls or moves past the area he's meant to open for you and the way closes behind him. 1.5 supposedly fixed it but the only way to notice the difference is likely to reroll and do the quest again, or just use the console on PC to move the priest back to you.