diff --git a/src/vs/platform/configuration/common/model.ts b/src/vs/platform/configuration/common/model.ts
index a981336a59d..a3c6df777b1 100644
--- a/src/vs/platform/configuration/common/model.ts
+++ b/src/vs/platform/configuration/common/model.ts
@@ -13,28 +13,29 @@ export function getDefaultValues(): any {
 
 	for (let key in properties) {
 		let value = properties[key].default;
-		addToValueTree(valueTreeRoot, key, value);
+		addToValueTree(valueTreeRoot, key, value, message => console.error(`Conflict in default settings: ${message}`));
 	}
 
 	return valueTreeRoot;
 }
 
-export function toValuesTree(properties: { [qualifiedKey: string]: any }): any {
+export function toValuesTree(properties: { [qualifiedKey: string]: any }, conflictReporter: (message: string) => void): any {
 	const root = Object.create(null);
 
 	for (let key in properties) {
-		addToValueTree(root, key, properties[key]);
+		addToValueTree(root, key, properties[key], conflictReporter);
 	}
 
 	return root;
 }
 
-function addToValueTree(settingsTreeRoot: any, key: string, value: any): void {
+function addToValueTree(settingsTreeRoot: any, key: string, value: any, conflictReporter: (message: string) => void): void {
 	const segments = key.split('.');
 	const last = segments.pop();
 
 	let curr = settingsTreeRoot;
-	segments.forEach(s => {
+	for (let i = 0; i < segments.length; i++) {
+		let s = segments[i];
 		let obj = curr[s];
 		switch (typeof obj) {
 			case 'undefined':
@@ -43,13 +44,16 @@ function addToValueTree(settingsTreeRoot: any, key: string, value: any): void {
 			case 'object':
 				break;
 			default:
-				console.error(`Conflicting configuration setting: ${key} at ${s} with ${JSON.stringify(obj)}`);
+				conflictReporter(`Ignoring ${key} as ${segments.slice(0, i + 1).join('.')} is ${JSON.stringify(obj)}`);
+				return;
 		}
 		curr = obj;
-	});
+	};
 
 	if (typeof curr === 'object') {
 		curr[last] = value; // workaround https://github.com/Microsoft/vscode/issues/13606
+	} else {
+		conflictReporter(`Ignoring ${key} as ${segments.join('.')} is ${JSON.stringify(curr)}`);
 	}
 }
 
diff --git a/src/vs/platform/configuration/node/configurationService.ts b/src/vs/platform/configuration/node/configurationService.ts
index a6d45964518..fd08d96a29a 100644
--- a/src/vs/platform/configuration/node/configurationService.ts
+++ b/src/vs/platform/configuration/node/configurationService.ts
@@ -104,7 +104,7 @@ export class ConfigurationService<T> implements IConfigurationService, IDisposab
 
 	private consolidateConfigurations(): ICache<T> {
 		const defaults = getDefaultValues();				// defaults coming from contributions to registries
-		const user = toValuesTree(this.rawConfig.getConfig());	// user configured settings
+		const user = toValuesTree(this.rawConfig.getConfig(), message => console.error(`Conflict in user settings: ${message}`));	// user configured settings
 
 		const consolidated = objects.mixin(
 			objects.clone(defaults), 	// target: default values (but dont modify!)
diff --git a/src/vs/workbench/api/node/extHostConfiguration.ts b/src/vs/workbench/api/node/extHostConfiguration.ts
index 32d39cf84c5..ae94fb8329e 100644
--- a/src/vs/workbench/api/node/extHostConfiguration.ts
+++ b/src/vs/workbench/api/node/extHostConfiguration.ts
@@ -35,7 +35,7 @@ function createUsefulConfiguration(data: IWorkspaceConfigurationValues): { data:
 			valueMap[key] = data[key].value;
 		}
 	}
-	const valueTree = toValuesTree(valueMap);
+	const valueTree = toValuesTree(valueMap, message => console.error(`Conflict in configuration settings: ${message}`));
 	return {
 		data,
 		valueTree
diff --git a/src/vs/workbench/services/configuration/common/model.ts b/src/vs/workbench/services/configuration/common/model.ts
index 85ca3f0a7a4..466751a606c 100644
--- a/src/vs/workbench/services/configuration/common/model.ts
+++ b/src/vs/workbench/services/configuration/common/model.ts
@@ -16,11 +16,11 @@ export interface IConfigFile {
 	parseError?: any;
 }
 
-export function newConfigFile(value: string): IConfigFile {
+export function newConfigFile(value: string, fileName: string): IConfigFile {
 	try {
 		const contents = json.parse(value) || {};
 		return {
-			contents: toValuesTree(contents),
+			contents: toValuesTree(contents, message => console.error(`Conflict in settings file ${fileName}: ${message}`)),
 			raw: contents
 		};
 	} catch (e) {
diff --git a/src/vs/workbench/services/configuration/node/configurationService.ts b/src/vs/workbench/services/configuration/node/configurationService.ts
index 8bbe0bb8c48..1c05bcc5d50 100644
--- a/src/vs/workbench/services/configuration/node/configurationService.ts
+++ b/src/vs/workbench/services/configuration/node/configurationService.ts
@@ -253,7 +253,7 @@ export class WorkspaceConfigurationService implements IWorkspaceConfigurationSer
 					return []; // never fail this call
 				}
 			}).then((contents: IContent[]) => {
-				contents.forEach(content => this.workspaceFilePathToConfiguration[this.contextService.toWorkspaceRelativePath(content.resource)] = TPromise.as(newConfigFile(content.value)));
+				contents.forEach(content => this.workspaceFilePathToConfiguration[this.contextService.toWorkspaceRelativePath(content.resource)] = TPromise.as(newConfigFile(content.value, content.resource.toString())));
 			}, errors.onUnexpectedError);
 		}
 
@@ -298,7 +298,7 @@ export class WorkspaceConfigurationService implements IWorkspaceConfigurationSer
 					break;
 				case FileChangeType.UPDATED:
 				case FileChangeType.ADDED:
-					this.workspaceFilePathToConfiguration[workspacePath] = resolveContent(resource).then(content => newConfigFile(content.value), errors.onUnexpectedError);
+					this.workspaceFilePathToConfiguration[workspacePath] = resolveContent(resource).then(content => newConfigFile(content.value, content.resource.toString()), errors.onUnexpectedError);
 					affectedByChanges = true;
 			}
 		}
diff --git a/src/vs/workbench/test/node/api/extHostConfiguration.test.ts b/src/vs/workbench/test/node/api/extHostConfiguration.test.ts
index 6eaf22734ae..50720b7a321 100644
--- a/src/vs/workbench/test/node/api/extHostConfiguration.test.ts
+++ b/src/vs/workbench/test/node/api/extHostConfiguration.test.ts
@@ -156,12 +156,24 @@ suite('ExtHostConfiguration', function () {
 	});
 
 	test('bogous data, #15834', function () {
-		const shape = new RecordingShape();
-		const allConfig = createExtHostConfiguration({
-			['editor.formatOnSave']: createConfigurationValue(true),
-			['editor.formatOnSave.extensions']: createConfigurationValue(['ts'])
-		}, shape);
+		let oldLogger = console.error;
+		let errorLogged = false;
 
+		// workaround until we have a proper logging story
+		console.error = (message, args) => {
+			errorLogged = true;
+		};
+		let allConfig;
+		try {
+			const shape = new RecordingShape();
+			allConfig = createExtHostConfiguration({
+				['editor.formatOnSave']: createConfigurationValue(true),
+				['editor.formatOnSave.extensions']: createConfigurationValue(['ts'])
+			}, shape);
+		} finally {
+			console.error = oldLogger;
+		}
+		assert.ok(errorLogged);
 		assert.ok(allConfig.getConfiguration('').has('editor.formatOnSave'));
 		assert.ok(!allConfig.getConfiguration('').has('editor.formatOnSave.extensions'));
 	});