Had same issue but found the solution... DO NOT use the add level feature of the trainer... If you go over level 100 the issue happens and the only way to correct it is to start an entirely new game from scratch. This also affects NG+ game saves that are carried over into the new game... Instaed, JUST use the add XP... It will then cap at lvl 100 and the game works fine.Too bad really, because lvl 250 is a one hit kill for even the most difficult of monsters..
I may have found a solution for this problem. I used the trainer and adjusted the amount of level added to negate Geralt back under level 100, I was then able to pick up the quest item. Then I downloaded the mod that allowed levels over 100, and boosted my level back up from there. So far so good. I am able to pick up quest items again.
Thank you for this. I would never have found the solution if you didn't outline what the problem was.
Thank you too, CyPHeR369. Didn't realize there was a mod for that.
[Edited by MartyrsDieYoung, 1/5/2019 12:45:07 AM]
I hope that this will work I have the same problem that quest items do not appear at all when I use the witcher senses, currently happening in the quest jenny of the woods, the letter doesn´t appear in the grave. That doesn´t happen in all quests though. Hope that I won´t have to start a new game. Thank you for the solution.