when i just upgraded factorio from 0.16.25 to 0.16.28, i couldn't start the program without getting this error

failed to load mods:
error while loading item prototype "science-pack-1" (tool):
Prototype "science-pack-1" registered twice
disable all mods / restart / exit

no specific mod was given in that message, but after disabling this mod (by editing the mod-list.json manually), factorio could be started again.

while using factorio 0.16.25 with this mod, i had noticed some strange effects (which wouldn't break the game, but might be connected to the new bug): when using helmod to calculate some production chain, and also on other occasions, the liquid and the science bottles were both shown as the same icon and name and/or the wrong one was shown/used. having the same (bad) prototype for both might be an explanation of those glitches, and some new check in the new factorio finally notices such problems.

I'll look at this, it's possible that fluids have to have a different prototype name now. Currently the fluids and the items have the same prototype names

Edit: it looks like they have different prototypes and I can start the game on 0.16.36, hmm

Edit edit: Yeah the fluids have the same name

Should be fixed in the next update