For The Love Of Treviso/The Eternal Hymn not loading.

I am currently on the main questline mission, "For The Love Of Treviso", but unfortunately whenever I try and load into Treviso the game either presents me with a black screen or with a loading screen that doesn't actually load. It seems to be doing it with my Harding mission as well, "The Eternal Hymn". Nothing ever loads, but the game never actually crashes, so I have to Ctrl-Alt-Del to exit the game. The only other quest I have available currently is Lucanis's "A Murder Of Crows", which can't be started until the main questline one is done. So I am currently at a standstill with any gameplay, as I also don't have any other companion or faction quests to do as I did any I had thinking maybe they were conflicting. 

Any ideas on what to do?