Hi there! I understand you're having trouble downloading YouTube videos and searching for them in the Tubidy Fm Offline Music Player. Let’s work through this together.

1. Check Your Internet Connection: Sometimes a weak or unstable connection can prevent downloads or searches. Make sure you're connected to Wi-Fi or have a strong cellular signal.

2. Update the Tubidy App: Ensure that you have the latest version of the Tubidy app installed. Go to the App Store, search for Tubidy Fm Offline Music Player, and see if there’s an update available.

3. Clear Cache: Sometimes, clearing the app's cache can help resolve issues. Unfortunately, iOS doesn't provide a direct option to clear the app cache like Android does, but reinstalling the app might help. You can uninstall it and then reinstall it from the App Store.

4. Check Your Storage: Ensure that you have sufficient storage space on your device. If your storage is full, the app may not function properly. You can check your storage in Settings > General > iPhone Storage.

5. Application Permissions: Make sure that Tubidy has the necessary permissions to access your device’s storage for downloads.

6. Try Rebooting: A quick reboot of your iPhone can refresh the app's functionality.

If you've tried these steps and still can't download or search for YouTube videos, please let me know what you've already attempted! That way I can guide you further. Are you satisfied with the solution I provided so far?