Sync related errors
The World Wide Web Publishing Service (W3SVC) is stopped.

Internet Information Services (IIS) Manager
The World Wide Web Publishing Service (W3SVC) is stopped.
Websites cannot be started unless the World Wide Web Publishing Service (W3SVC) is running.
Fix
- Press Win + R
- Type services.msc and press Enter
- Locate World Wide Web Publishing Service
- Right-click → Start

401 Unauthorized Error
This occurs when no username and password are provided. Even if IIS is configured to allow access for all users, you must still enter your computer’s username and password in TimyNote’s sync settings.
Invalid response: 405 Method Not Allowed
WebDAV is not enabled. Enable your WebDAV by referring this tutorial.