Hey Michelle, sorry to hear you’re dealing with this frustrating mess on your Galaxy A5 2016—storage bloat crashing WhatsApp and locking up your phone is the worst kind of tech headache. Let’s walk through fixing this step by step, starting with getting your device back up and running right now.

Since your phone won’t shut down, exit WhatsApp, or even take calls, a forced restart is your only immediate fix here:

• Press and hold the Power button + Volume Down button together for 7-10 seconds.
• Keep holding until you see the Samsung logo appear—this will force the device to reboot, breaking the unresponsive loop.

A full internal storage is almost certainly triggering the WhatsApp crashes and system glitches. Let’s free up space quickly and safely:

• Use Samsung’s built-in storage analyzer: Head to Settings > Device Maintenance > Storage (or just Settings > Storage on older One UI versions). This will show you a breakdown of what’s eating up space—photos, videos, apps, cached data, etc.
• Delete large, unnecessary files first: Prioritize downloaded videos, duplicate photos, or unused apps you haven’t touched in months. For media you want to keep, move it to an SD card (your A5 2016 supports expandable storage) to free up internal space.
• Clear cached data for all apps: In the Storage menu, tap Cached data and confirm deletion. This removes temporary app files (safe—won’t delete your personal data) and can free up several gigabytes instantly.

With some free space now, let’s target WhatsApp specifically to stop the crashes:

• Clear WhatsApp’s cache first: Go to Settings > Apps > WhatsApp > Storage > Clear Cache. This fixes minor crash bugs without losing any of your chat history.
• If crashes persist, clear WhatsApp’s data (back up first!): Before doing this, open WhatsApp and go to Settings > Chats > Chat backup to save your conversations to Google Drive or local storage (make sure you have enough space for the backup). Then head back to the app’s storage settings and tap Clear Data. Reopen WhatsApp and restore your backup.
• Update WhatsApp to the latest version: Open the Google Play Store, search for WhatsApp, and tap Update if available. Outdated versions often have unresolved bugs that cause crashes—updating can fix this instantly.
• As a last resort, uninstall and reinstall WhatsApp: Again, back up your chats first. Then go to Settings > Apps > WhatsApp > Uninstall, reinstall from the Play Store, and restore your backup.

To keep this from happening again, set up these safeguards:

• Tweak WhatsApp’s auto-download settings: Go to WhatsApp > Settings > Storage and data and turn off auto-download for photos/videos when using mobile data (or limit it to Wi-Fi only). You can also enable Auto-delete old messages to automatically remove older chats after 30 days or 1 year.
• Regularly clean WhatsApp media: Use the Manage storage option in WhatsApp’s Storage and data settings to see which chats are taking up the most space. You can bulk-delete unnecessary photos, videos, and documents from here.
• Set SD card as default storage: Go to Settings > Storage > Default storage location and select your SD card for photos, videos, and downloads. This ensures new media doesn’t clog up your internal storage over time.

内容的提问来源于stack exchange，提问作者Michelle