Please forgive me if this topic has been posted but my problem is very specific! I am trying to complete the mission from the Dark Brotherhood called breaching security. I can kill Gaius that is not an issue but when I try to plant anything on him it doesn't give me the option to open a pickpocket screen or a inventory screen on him or anything. Either in sneak mode or not it doesn't do anything when I hover the cursor over his body. It has no options available. I have noticed this with other victims I have assassinated on the dark brotherhood quests as well. On them however it did not require me to do anything with the bodies to complete the quest until I came to this one. I have about 10-15 different mods loaded so I thought maybe that was it but then I tried starting Skyrim with the regular skyrim program rather than the mod manager and it still doesn't work. Does anyone know of any mods out there that will cause this problem? Should I reload skyrim with no mods and start over? I am not sure what to do. Oh by the way I did open the console and try the setObjectiveCompleted to force the plant of the letter on Gaius and it said it did but then I will get back to the Sanctuary and Gabriella still tells me I need to go and kill Gaius even though I already did this. I have googled and googled several solutions and nothing has worked. Help would be appreciated. Thank you

That isn't going to disable your mods. You have to uncheck them in the mod manager. Can you generally loot/open inventory on any npc you kill?

Yes I can it is just on any that I have an assassination contract on from the Dark Brotherhood.