Your lock Screen may be disabled I'm not sure but try these options...
1. Go to the Settings menu on your device.2. Scroll down until you find “Security” or “Lock Screen and Security” and tap it. This is typically located under the “Personal” section on Android 4.2 or higher.3. Under the “Screen Security” section, tap the Screen Lock Type option. By default, this option is set to “Swipe,” which means no password or pattern is needed.
From here, select which lock type you want to use:
Pattern: swipe to draw an unlock pattern you want to use. If you messed up, hit retry. Otherwise, hit continue. It will then ask you to draw that pattern again to confirm.PIN: insert a 4-digit PIN that you’re comfortable with. It’s a good idea not to use repeating numbers (don’t use more than two if you absolutely must). Hit continue. Re-enter the PIN to confirm.Password: type the password you’re comfortable with. The password must be at least 4 characters, must be no more than 17 characters, and must contain at least 1 letter. Use an alphanumerical password with symbols that’s at least 8 characters long for ultimate security, but anything will do. Hit continue. Re-enter the password to confirm.Fingerprints: If available on your phone, a PIN or Password must be set as a backup before you can enable Fingerprint Security
OR
1. From a Home screen, swipe up from the center of
the display to access the apps screen
-> These instructions only apply to Standard
mode and the default Home screen !ayout.
2. Navigate: Settings 0 > Lock screen
3. Tap Screen lock type
> If presented, enter the current PIN, password
or pattern.
4. Tap Pattern.
5. Draw an unlock pattern (connecting at least 4
dots) then tap Continue.
6. Draw the same pattern again then tap Confirm
*Hope This Helps.Let Me Know If It Does 🙂
