Hi there! I understand you're trying to get a free chapter by reading articles on the MoboReader app, but you're encountering an error message. To help you better, could you let me know exactly what the failure message says? Also, are you trying this on Wi-Fi or mobile data? This info will help me guide you precisely.

Meanwhile, here are a few easy steps to try:

1. Restart the MoboReader app: Close it completely and reopen. Sometimes this clears minor glitches.
2. Check your internet connection: Switch between Wi-Fi and cellular data to see if the issue persists.
3. Update the app: Make sure your MoboReader app is up to date in the App Store. App updates often fix bugs.
4. Clear app cache: On iOS, you might try logging out and back into your account to refresh cached data.
5. Confirm free chapter limits: Sometimes, the app limits how many free chapters you can unlock in a given period. If you've reached a limit, this might cause the error.

If these don’t work, it could be something on the backend or account-related. Let me know if the error message includes anything about your account status or if you see any time limits.

Are you able to try these steps and tell me what happens? I’m here to help you get this resolved!