diff --git a/scripts/generateLayerOverview.ts b/scripts/generateLayerOverview.ts
index 5d1a088df..85890487e 100644
--- a/scripts/generateLayerOverview.ts
+++ b/scripts/generateLayerOverview.ts
@@ -442,29 +442,30 @@ class LayerOverviewUtils {
 
                 if (themeFile.icon.endsWith(".svg")) {
                     try {
-                        ScriptUtils.ReadSvgSync(json.icon, (svg) => {
+                        ScriptUtils.ReadSvgSync(themeFile.icon, (svg) => {
                             const width: string = svg.$.width
                             const height: string = svg.$.height
+                            const err = themeFile.hideFromOverview ? console.warn : console.error
                             if (width !== height) {
                                 const e =
-                                    `the icon for theme ${json.id} is not square. Please square the icon at ${json.icon}` +
+                                    `the icon for theme ${themeFile.id} is not square. Please square the icon at ${themeFile.icon}` +
                                     ` Width = ${width} height = ${height}`
-                                ;(json.hideFromOverview ? warnings : errors).push(e)
+                                err(e)
                             }
 
                             const w = parseInt(width)
                             const h = parseInt(height)
                             if (w < 370 || h < 370) {
                                 const e: string = [
-                                    `the icon for theme ${json.id} is too small. Please rescale the icon at ${json.icon}`,
+                                    `the icon for theme ${themeFile.id} is too small. Please rescale the icon at ${themeFile.icon}`,
                                     `Even though an SVG is 'infinitely scaleable', the icon should be dimensioned bigger. One of the build steps of the theme does convert the image to a PNG (to serve as PWA-icon) and having a small dimension will cause blurry images.`,
                                     ` Width = ${width} height = ${height}; we recommend a size of at least 500px * 500px and to use a square aspect ratio.`,
                                 ].join("\n")
-                                ;(json.hideFromOverview ? warnings : errors).push(e)
+                                err(e)
                             }
                         })
                     } catch (e) {
-                        console.error("Could not read " + json.icon + " due to " + e)
+                        console.error("Could not read " + themeFile.icon + " due to " + e)
                     }
                 }
 
diff --git a/scripts/slice.ts b/scripts/slice.ts
index 041619c8d..214f5dad0 100644
--- a/scripts/slice.ts
+++ b/scripts/slice.ts
@@ -76,7 +76,7 @@ async function readGeojsonLineByLine(inputFile: string): Promise<any[]> {
 
 async function readFeaturesFromGeoJson(inputFile: string): Promise<any[]> {
     try {
-        return JSON.parse(fs.readFileSync(inputFile, "UTF-8")).features
+        return JSON.parse(fs.readFileSync(inputFile, { encoding: "utf-8" })).features
     } catch (e) {
         // We retry, but with a line-by-line approach
         return await readGeojsonLineByLine(inputFile)