Studio: studio now supports loading self-made layers in themes

src/Models/ThemeConfig/Conversion/Conversion.ts

@@ -39,7 +39,7 @@ export abstract class Conversion<TIn, TOut> {
             ConversionContext.print(msg)
         }
         if (context.hasErrors()) {
-            throw "Detected one or more errors, stopping now"
+            throw new Error(["Detected one or more errors, stopping now:", context.getAll("error").map(e => e.context.path.join(".")+": "+e.message)].join("\n\t"))
         }
         return fixed
     }

src/Models/ThemeConfig/Conversion/PrepareTheme.ts

@@ -186,7 +186,7 @@ class AddDefaultLayers extends DesugaringStep<LayoutConfigJson> {
 
     convert(json: LayoutConfigJson, context: ConversionContext): LayoutConfigJson {
         const state = this._state
-        json.layers = [...(json.layers ?? [])]
+        json.layers = Utils.NoNull([...(json.layers ?? [])])
         const alreadyLoaded = new Set(json.layers.map((l) => l["id"]))
 
         for (const layerName of Constants.added_by_default) {