Create a new text file named exactly resource.cfg (no .txt extension) inside the Mods folder, with this content:
For pre-made configurations and detailed installation guides, the community at Mod The Sims provides the most reliable legacy support for The Sims Medieval modding. The Sims 4 resource.cfg File - thesimsresource - Zendesk sims medieval resource.cfg
The Sims 3’s default resource.cfg often uses: Create a new text file named exactly resource