diff --git a/src/vs/code/electron-main/window.ts b/src/vs/code/electron-main/window.ts
index 9fd10acf1e8..4821653f75b 100644
--- a/src/vs/code/electron-main/window.ts
+++ b/src/vs/code/electron-main/window.ts
@@ -409,7 +409,7 @@ export class CodeWindow extends Disposable implements ICodeWindow {
 				return callback({ cancel: true });
 			}
 
-			return callback({ cancel: false, responseHeaders });
+			return callback({ cancel: false });
 		});
 
 		// Remember that we loaded
diff --git a/src/vs/platform/request/common/request.ts b/src/vs/platform/request/common/request.ts
index 81ec255e65b..5ddf08de7bf 100644
--- a/src/vs/platform/request/common/request.ts
+++ b/src/vs/platform/request/common/request.ts
@@ -48,7 +48,13 @@ export async function asJson<T = {}>(context: IRequestContext): Promise<T | null
 		return null;
 	}
 	const buffer = await streamToBuffer(context.stream);
-	return JSON.parse(buffer.toString());
+	const str = buffer.toString();
+	try {
+		return JSON.parse(str);
+	} catch (err) {
+		err.message += ':\n' + str;
+		throw err;
+	}
 }
 
 
diff --git a/src/vs/workbench/contrib/webview/electron-browser/webviewElement.ts b/src/vs/workbench/contrib/webview/electron-browser/webviewElement.ts
index 64a256b3fca..40df3900401 100644
--- a/src/vs/workbench/contrib/webview/electron-browser/webviewElement.ts
+++ b/src/vs/workbench/contrib/webview/electron-browser/webviewElement.ts
@@ -100,7 +100,7 @@ class WebviewSession extends Disposable {
 						return;
 					}
 				}
-				callback({ cancel: false, responseHeaders: details.responseHeaders });
+				callback({ cancel: false });
 			});
 		}));
 	}