Ideas
My Sim cannot finish a book every time she tries too. This issue was apparently fixed but I am experiencing it much more often than I did previously. I am able to write 1 book after trying & failing to write 5+ books.
My Sim will write until the book is nearly complete then the task just cancels, she does not get distracted or stop on her own. Then when I tell her to continue the book the task appears for a second & she sits at the computer but then the task cancels & disappears, my sim will get a little likes writing bubble appear above her head like she is writing but she is not.
I have tried this save vanilla and it is still happening.
I have exactly the same problem, has been happening for some time. I had a look at my sims buffs and there's no writer's block (they can start a new book also), they just simply won't finish some books.