I also get the same black sphere and fire particle on installed folder.
I dont know why i didnt realise this quicker, but the PU effect files were stored in the .ark files that gen1 released, but i had too take them out until we could edit them due to the files in the .arks loading with the engine instead of the dynamic resource system which crashed because materials are broken.
Wow, your barrels effects look crap in the installed Gen2 lol
Will have to try and sort them out for next update or one after
Anyway, all the black spheres and non material'd effects is due to you using a particle universe file and code in the barrel. My advice would be to use SkyParticles instead however, be aware loading them from script as they do differ in code to call them. Check out StarFire's post on the correct way to call a sky particle in script:
http://www.forum.aurasoft-skyline.co.uk/viewtopic.php?f=41&t=1772#p9698Q) Are you using damage actions or specific actions to trigger the particles or is it in script.
Hope this helps