12 months ago - AndrewT - Direct link
Toxoids need the patch it was released with, 3.5  
12 months ago - AndrewT - Direct link
I can't explain how you could have played using Toxoids with 3.4.5 before, but that's clearly not the case now!

You could check with the good folks in User Mods on how to remove the requirement for that DLC from the save game file.