WhatsApp for Xiaomi Mi Max

MIUI's aggressive memory management is usually the culprit, so go to Settings > Apps > Manage apps > WhatsApp > Battery saver and set it to No restrictions, then enable Autostart for WhatsApp on that same app page. Next, tap Clear data and choose Clear cache (not Clear all data) so you don't lose chats, and make sure WhatsApp is updated to the latest version from the Play Store. If it still crashes immediately on launch, uninstall and reinstall while keeping your local backup so chats restore. See how others solved this on Reddit

MIUI updates often reset app permissions and battery rules, so re-grant everything under Settings > Apps > Manage apps > WhatsApp > Permissions (Contacts, Storage, Phone, and Notifications all allowed). Also set Battery saver to No restrictions and turn on Autostart for WhatsApp on the same app page, since the update likely re-locked it. Finally, clear the WhatsApp cache and reboot the phone to let the new build settle. See how others solved this on Reddit

This is almost always a storage permission issue introduced by the update, so go to Settings > Apps > Manage apps > WhatsApp > Permissions and make sure Files and media (Storage) is set to Allow. Then confirm you have free storage space on the phone, and in WhatsApp open Settings > Storage and data > Media auto-download and enable it for mobile data and Wi-Fi. If media still won't save, clear the WhatsApp cache and restart, which lets it rebuild the media folder. See how others solved this on Reddit

This usually happens when WhatsApp loses sync with your phonebook or a SIM/Google contacts merge goes wrong, so first confirm WhatsApp has Contacts permission under Settings > Apps > Manage apps > WhatsApp > Permissions. Then open WhatsApp, tap the new-chat icon and use the menu's refresh option to re-sync names from your phonebook. If names are still mixed up, open the Contacts app > Settings, run Merge duplicate contacts, and set your Google account as the default storage so WhatsApp reads a clean list. See how others solved this on Reddit

MIUI kills background apps and widgets to save battery, so go to Settings > Apps > Manage apps > WhatsApp, enable Autostart, and set Battery saver to No restrictions so the widget can refresh. Also lock WhatsApp in the recent-apps view (open Recents, swipe down on the WhatsApp card and tap the lock icon) to stop the system from clearing it. After that, remove and re-add the widget from the home-screen widget menu so it re-registers. See how others solved this on Reddit