hello everyone, I have a problem in the quest conjuration ritual spell quest, on the roof when it is to do the summon to dremora, did the 1st time all went well, the second also, now the third time is no longer possible to map the summon, and not have to load the previous game, will have been because of lydia? she attacked the dremora, the quest this bug and wanted to have a dremora, I had plenty of time to evolve conjuration to 100 to have the final quest bugged.

Anyone know the solution for this? grateful thanks