Thank you! After exploring a little I figured out that Gradle's runClient did load my resources, so I'm using build+runClient tasks to solve the problem.
Hello! I've followed this guy's guide religiously and Forge isn't loading my mod's resources at runtime (although, the mod .jar has resources' files). I only came because topics of this type of problem are old and their solution didn't work. I've reinstalled JDK 8 and tried to go to Eclipse, but even switching the IDE didn't work (which surprised me). I don't know if it has something with my PC, because it was working on my laptop (I've done the same setup on both of them). I'm really clueless, I've redone the setup a hundred times already. I was even thinking if I can copy the compiled .jar for FML to load instead of the runtime one. I should call it Missing Resources now lol