@rathma86 All you have to do is fast travel to Norway and back to England. Hope this helps!

Ps: this helped me several times when a side quest world event got bugged, etc.

@heartbreak02007 I had the longboat on the road too. But other than that I had no troubles continuing with the mission. I rode on my mount to the castle and finished the assault. Glad I could help

I FOUND A FIX!!!!!!

At least it worked for me... All you have to do is fast travel to Norway and back to England. Hope this helps!

Ps: this helped me several times when a side quest world event got bugged, etc.