Got some bad news: I was able to reproduce this bug (some of the time) but I don’t have the blazemod mod enabled (just Dark Days Ahead, Tall Buildings, Vehicle Additions Pack, Tanks and Other Vehicles, Boats, Folding Parts, Filthy Clothing, Mutant NPCs, No Flaming Weapons, No Survivor Armor, and NPC traits)
I loaded up my recent game, walked over and picked up two rocks (without any problems), but then any new rocks just didn’t appear in my inventory. I did look, and while they were on the ground they appeared in the ‘AMMO’ category, and when I pushed ‘e’ and then ‘a’ (to select the rock), the weight and volume estimates updated to reflect what my weight and volume would be after picking up the rock, but when I pressed ‘enter’, nothing happened, except that the rock disappeared from the ground.
I have a 10MB RARed save file if anyone would like to look at it, but don’t know the best way to get it to you.