Game won't launch with Cerys installed.
Factorio Space Age 2.0.54

Failed to load mods: Error while running setup for technology prototype "cerys-holmium-plate-productivity-1-2" (technology): Technology prerequisite "cerys-holmium-plate-productivity-1" is registered more than once.

mod-list.json

{
  "mods": 
  [

    {
      "name": "base",
      "enabled": true
    },

    {
      "name": "elevated-rails",
      "enabled": true
    },

    {
      "name": "quality",
      "enabled": true
    },

    {
      "name": "space-age",
      "enabled": true
    },

    {
      "name": "Cerys-Moon-of-Fulgora",
      "enabled": true
    },

    {
      "name": "ExpandedProductivityResearch",
      "enabled": true
    },

    {
      "name": "Flare Stack",
      "enabled": true
    },

    {
      "name": "PlanetsLib",
      "enabled": true
    }
  ]
}

Thanks for your report. This issue is fixed in V1.1.1.
Compatibility with mods that add their own productivity tech chains should generally be improved and no longer lead to crashes.