https://us.community.samsung.com/t5/Galaxy-S21/My-S21-Ultra-Won-t-unlock-after-update-OS-15/m-p/3365207#M97198 <P>After updating my S21 Ultra to Android 15, when I enter my PIN, a black screen appears and I'm prompted to enter the PIN again.</P><P>If I enter the PIN incorrectly, I get the message "Incorrect PIN." Can you help me resolve this issue?</P><P>#edit:After trying to log in about 20 times, the phone eventually unlocks, but then gets stuck on the phone is starting.<span class="lia-inline-image-display-wrapper lia-image-align-right" image-alt="20250923_213634.jpg" style="width: 487px;"><img src="https://us.community.samsung.com/t5/image/serverpage/image-id/1281926i0E3697C1CA827F4B/image-size/large?v=v2&amp;px=999" role="button" title="20250923_213634.jpg" alt="20250923_213634.jpg" /></span></P> Tue, 23 Sep 2025 18:58:00 GMT Kuro2 2025-09-23T18:58:00Z