When I was joining my World in Unleashed today after a week, I couldn't use Thaumcraft, as the research in the Thaumonomicon was the same as on my Server I'm sometimes playing on. Neither Restarting the game multiple times nor restarting the PC, or Deleting and Reinstalling the modpack helped.
Even newly created worlds happened to have the same research. I don't know what's left that I could do now.
Even newly created worlds happened to have the same research. I don't know what's left that I could do now.