diff --git a/scripts/ScriptUtils.ts b/scripts/ScriptUtils.ts
index 043cfee1f2..36e3b55214 100644
--- a/scripts/ScriptUtils.ts
+++ b/scripts/ScriptUtils.ts
@@ -205,6 +205,10 @@ export default class ScriptUtils {
         headers?: any,
         timeoutSecs?: number
     ): Promise<{ content: string } | { redirect: string } | "timeout"> {
+        if (url === undefined || url === null) {
+            console.trace("URL is null or undefined")
+            throw ("Invalid url: " + url)
+        }
         if (url.startsWith("./assets")) {
             return Promise.resolve({ content: readFileSync("./public/" + url, "utf8") })
         }
diff --git a/src/Models/SourceOverview.ts b/src/Models/SourceOverview.ts
index 831e7f0a22..47efe999e6 100644
--- a/src/Models/SourceOverview.ts
+++ b/src/Models/SourceOverview.ts
@@ -10,7 +10,9 @@ import ThemeConfig from "../../src/Models/ThemeConfig/ThemeConfig"
 import { ThemeConfigJson } from "../../src/Models/ThemeConfig/Json/ThemeConfigJson"
 import SpecialVisualizations from "../../src/UI/SpecialVisualizations"
 import ValidationUtils from "../../src/Models/ThemeConfig/Conversion/ValidationUtils"
-import { QuestionableTagRenderingConfigJson } from "../../src/Models/ThemeConfig/Json/QuestionableTagRenderingConfigJson"
+import {
+    QuestionableTagRenderingConfigJson
+} from "../../src/Models/ThemeConfig/Json/QuestionableTagRenderingConfigJson"
 import { LayerConfigJson } from "../../src/Models/ThemeConfig/Json/LayerConfigJson"
 
 export interface ServerSourceInfo {
@@ -66,7 +68,7 @@ export class SourceOverview {
             }
             const neededUrls = usedSpecialVisualisation.func.needsUrls ?? []
             if (typeof neededUrls === "function") {
-                let needed: string | string[] | ServerSourceInfo | ServerSourceInfo[] = neededUrls(
+                const needed: string | string[] | ServerSourceInfo | ServerSourceInfo[] = neededUrls(
                     usedSpecialVisualisation.args
                 )
                 if (Array.isArray(needed)) {
@@ -105,11 +107,11 @@ export class SourceOverview {
             const url = f.properties.url
             const match = url.match(regex)
 
-            const packageInInfo = (url: string) => {
-                if (typeof url !== "string") {
-                    throw "invalid url" + url
+            const packageInInfo: (url: (string | string[])) => ServerSourceInfo[] = (urls: string | string[]) => {
+                if (typeof urls === "string") {
+                    urls = [urls]
                 }
-                return <ServerSourceInfo>{
+                return urls.map(url => <ServerSourceInfo>{
                     url,
                     description:
                         "Background layer source or supporting sources for " + f.properties.id,
@@ -119,18 +121,25 @@ export class SourceOverview {
                         "https://github.com/osmlab/editor-layer-index",
                         f.properties?.attribution?.url,
                     ]),
+                })
+            }
+
+            const packageInInfoD: (url: (string | string[])) => (ServerSourceInfo[]) = (url: string | string[]) => {
+                if (!url) {
+                    return []
                 }
+                return packageInInfo(url)
             }
 
             if (match) {
                 const domains = match[1].split(",")
                 const subpart = match[0]
-                const info: ServerSourceInfo[] = domains.map((d) =>
+                const info: ServerSourceInfo[] = domains.flatMap((d) =>
                     packageInInfo(url.replace(subpart, d))
                 )
                 urls.push(...info)
             } else {
-                urls.push(packageInInfo(url))
+                urls.push(...packageInInfo(url))
             }
 
             if (f.properties.type === "vector") {
@@ -145,42 +154,46 @@ export class SourceOverview {
                 }
                 try {
                     console.log("Downloading ", url)
+                    urls.push(...packageInInfo(url))
                     const styleSpec = await Utils.downloadJsonCached(url, 1000 * 120, {
                         Origin: "https://mapcomplete.org",
                     })
                     for (const key of Object.keys(styleSpec?.["sources"] ?? {})) {
-                        const url = styleSpec["sources"][key].url
+                        let url = styleSpec["sources"][key].url
                         if (!url) {
                             continue
                         }
+                        console.log(">>> SPlitting", url)
+                        const split = url.split(",https://")
+                        console.log("Multisplit:", split)
+                        url = split[0]
                         let urlClipped = url
                         if (url.indexOf("?") > 0) {
                             urlClipped = url?.substring(0, url.indexOf("?"))
                         }
-                        console.log("Source url ", key, url)
-                        urls.push(packageInInfo(url))
+                        urls.push(...packageInInfo(url))
                         if (urlClipped.endsWith(".json")) {
                             const tileInfo = await Utils.downloadJsonCached(url, 1000 * 120, {
-                                Origin: "https://mapcomplete.org",
+                                Origins: "https://mapcomplete.org"
                             })
-                            urls.push(packageInInfo(tileInfo["tiles"] ?? []))
+                            urls.push(...packageInInfo(tileInfo["tiles"] ?? []))
                         }
                     }
                     urls.push(
                         ...(styleSpec["tiles"] ?? [])
                             .flatMap((ls) => ls)
-                            .map((url) => packageInInfo(url))
+                            .map((url) => packageInInfoD(url))
                     )
-                    urls.push(packageInInfo(styleSpec["sprite"]))
-                    urls.push(packageInInfo(styleSpec["glyphs"]))
+                    urls.push(...packageInInfoD(styleSpec["sprite"]))
+                    urls.push(...packageInInfoD(styleSpec["glyphs"]))
                 } catch (e) {
+                    console.error(e)
                     console.error(
-                        "ERROR: could not download a resource, some sprites might not be whitelisted and thus not load"
-                    )
+                        "ERROR: could not download a resource: " + url + "\nSome sprites might not be whitelisted and thus not load")
                 }
             }
         }
-        urls = urls.filter((item) => !!item.url)
+        urls = urls.filter((item) => !!item?.url)
         urls.sort((a, b) => (a < b ? -1 : 1))
         urls = Utils.DedupOnId(urls, (item) => item.url)
         this.eliUrlsCached = urls