WhatsApp for LG K10

First reboot the phone by holding the Power button, since a frozen lock screen sometimes rejects the right PIN until the system restarts. If it still refuses and no 'Forgot PIN' option or Google account unlock appears, your only reliable path is a factory reset from recovery: power off, then hold Power + Volume Down until the LG logo appears, release and re-hold briefly, then use the volume keys to select 'Wipe data/factory reset' and confirm with the Power button. This erases everything on the phone, so use it only as a last resort, and afterward you'll need your linked Google account to finish setup. See how others solved this on Reddit

Open Settings > Apps, pick your default Messaging app and tap Storage > Clear cache, then reopen the app and confirm the message center (SMSC) number under its Settings matches your carrier's. Also check that mobile data/signal is active and that your message storage isn't full, since a full inbox can block new sends, so delete old threads. If it persists, toggle Airplane mode on and off to re-register on the network, or power off and reinsert the SIM card. See how others solved this on Reddit

Skip the third-party 'WhatsApp for tablet' clones, as they often ask you to scan your account into an unofficial client and can get your number banned or your messages exposed. Instead use WhatsApp's official Linked Devices feature: on your LG K10 open WhatsApp > tap the three-dot Menu > Linked devices > Link a device, then scan the QR code shown on the tablet at web.whatsapp.com. This is the only sanctioned way to mirror your chats to a second screen. See how others solved this on Reddit

This usually means the proximity sensor near the top of the screen isn't being triggered, so WhatsApp never switches output to the earpiece. Wipe any screen protector film, dust or smudges off the sensor area above the display, and make sure a case isn't covering it. If it still won't switch, restart the phone and play a voice note while holding the K10 normally to your ear; if cleaning and rebooting don't help, a faulty proximity sensor is the likely cause. See how others solved this on Reddit

The K10's limited RAM struggles once storage fills up, so go to Settings > Apps > WhatsApp > Storage and tap Clear cache, then inside WhatsApp use Settings > Storage and data > Manage storage to delete large forwarded videos and files. Free up internal space by moving photos to a microSD card or Google Drive, and turn off media auto-download under WhatsApp Settings > Storage and data. A periodic reboot and closing background apps keeps an aging device like this more responsive. See how others solved this on Reddit

The K10 still handles calls, SMS and a current copy of WhatsApp fine, but it runs an old Android version that no longer receives security patches, so treat it as a basic or backup device rather than your main phone. Keep WhatsApp updated from the Play Store while it's still supported, avoid banking and other sensitive apps on it, and back up your chats via WhatsApp Settings > Chats > Chat backup to Google Drive. Once apps start refusing to install because of the old OS, that's the practical sign it's time to upgrade. See how others solved this on Reddit