Minecraft Version 1.12.2
Forge Version 14.23.2.2611
Mod Version 0.4.0-136
Describe your problem, including steps to reproduce it
Whenever the default Oil changes, PneumatiCraft causes a server tick loop without having anything from it placed:
https://pastebin.com/SEr8JH6u
I have gotten this on 2 occasions:

1. Having Imnersive Petroleum and PneumatiCtaft present where Immersive Petroleum's Oil was the default and then adding BuildCraft (which made it's Oil the default)
2. Yet again having those 2 mods present and adding GalactiCraft (making its Oil the default)

Yeah, this is a well-known recurring issue. PNC is sensitive to other mods adding oil fluids since it needs to do worldgen with oil fluid blocks by default. See #30 for a lot more discussion on this. In short, though you can either:

• Try to get PNC to load before all other oil-providing mods (see the above thread)
• Simply disable PNC's oil worldgen, and let PNC use the oil fluid from the other mod(s). If you're developing a skyblock pack, that's probably what you want anyway. See D:oilGenerationChance in pneumaticcraft.cfg.

Problem should be resolved in 0.4.1 release.