[Nexus 5X Original Android Development] CazeW:
Had an interesting bug with this version. I couldn't unlock my phone. After I entered the pin, the screen went black and returned to the lockscreen where it asked for the pin again. Going back to stock kernel fixed the problem.

EDIT: Snip from logcat. This seems to be the issue:

12-07 03:50:17.520 948 1504 E LockSettingsStorage: Cannot read file java.io.FileNotFoundException: /data/system_de/0/spblob/86694bdddd4854b0.weaver: open failed: ENOENT (No such file or directory)
12-07 03:50:17.524 782 782 D PermissionCache: checking android.permission.ACCESS_KEYGUARD_SECURE_STORAGE for uid=1000 => granted (1031 us)
12-07 03:50:17.540 761 761 D keystore: AddAuthenticationToken: timestamp = 50255 (5747719024431595520), time_received = 43
12-07 03:50:17.586 761 761 E keymaster1_device: Begin send cmd failed
12-07 03:50:17.586 761 761 E keymaster1_device: ret: 0
12-07 03:50:17.586 761 761 E keymaster1_device: resp->status: -30
12-07 03:50:17.588 761 761 E keymaster1_device: Abort send cmd failed
12-07 03:50:17.588 761 761 E keymaster1_device: ret: 0
12-07 03:50:17.588 761 761 E keymaster1_device: resp->status: -28
12-07 03:50:17.592 948 1504 W System.err: java.security.InvalidKeyException: Keystore operation failed
12-07 03:50:17.592 948 1504 W System.err: at android.security.KeyStore.getInvalidKeyException(KeyStore.java:760)
12-07 03:50:17.592 948 1504 W System.err: at android.security.KeyStore.getInvalidKeyException(KeyStore.java:781)
12-07 03:50:17.592 948 1504 W System.err: at android.security.keystore.KeyStoreCryptoOperationUtils.getInvalidKeyExceptionForInit(KeyStoreCryptoOperationUtils.java:54)
12-07 03:50:17.592 948 1504 W System.err: at android.security.keystore.KeyStoreCryptoOperationUtils.getExceptionForCipherInit(KeyStoreCryptoOperationUtils.java:89)
12-07 03:50:17.592 948 1504 W System.err: at android.security.keystore.AndroidKeyStoreCipherSpiBase.ensureKeystoreOperationInitialized(AndroidKeyStoreCipherSpiBase.java:265)
12-07 03:50:17.592 948 1504 W System.err: at android.security.keystore.AndroidKeyStoreCipherSpiBase.engineInit(AndroidKeyStoreCipherSpiBase.java:148)
12-07 03:50:17.592 948 1504 W System.err: at javax.crypto.Cipher.tryTransformWithProvider(Cipher.java:2664)
12-07 03:50:17.592 948 1504 W System.err: at javax.crypto.Cipher.tryCombinations(Cipher.java:2575)
12-07 03:50:17.592 948 1504 W System.err: at javax.crypto.Cipher$SpiAndProviderUpdater.updateAndGetSpiAndProvider(Cipher.java:2480)
12-07 03:50:17.592 948 1504 W System.err: at javax.crypto.Cipher.chooseProvider(Cipher.java:567)
12-07 03:50:17.592 948 1504 W System.err: at javax.crypto.Cipher.init(Cipher.java:975)
12-07 03:50:17.592 948 1504 W System.err: at javax.crypto.Cipher.init(Cipher.java:910)
12-07 03:50:17.592 948 1504 W System.err: at com.android.server.locksettings.SyntheticPasswordCrypto.decrypt(SyntheticPasswordCrypto.java:63)
12-07 03:50:17.593 948 1504 W System.err: at com.android.server.locksettings.SyntheticPasswordCrypto.decryptBlob(SyntheticPasswordCrypto.java:122)
12-07 03:50:17.593 948 1504 W System.err: at com.android.server.locksettings.SyntheticPasswordManager.decryptSPBlob(SyntheticPasswordManager.java:1040)
12-07 03:50:17.593 948 1504 W System.err: at com.android.server.locksettings.SyntheticPasswordManager.unwrapSyntheticPasswordBlob(SyntheticPasswordManager.java:906)
12-07 03:50:17.593 948 1504 W System.err: at com.android.server.locksettings.SyntheticPasswordManager.unwrapPasswordBasedSyntheticPassword(SyntheticPasswordManager.java:843)
12-07 03:50:17.593 948 1504 W System.err: at com.android.server.locksettings.LockSettingsService.spBasedDoVerifyCredential(LockSettingsService.java:2105)
12-07 03:50:17.593 948 1504 W System.err: at com.android.server.locksettings.LockSettingsService.doVerifyCredential(LockSettingsService.java:1553)
12-07 03:50:17.593 948 1504 W System.err: at com.android.server.locksettings.LockSettingsService.checkCredential(LockSettingsService.java:1526)
12-07 03:50:17.593 948 1504 W System.err: at com.android.internal.widget.ILockSettings$Stub.onTransact(ILockSettings.java:164)
12-07 03:50:17.593 948 1504 W System.err: at android.os.Binder.execTransact(Binder.java:697)
12-07 03:50:17.593 948 1504 W System.err: Caused by: android.security.KeyStoreException: Signature/MAC verification failed
12-07 03:50:17.593 948 1504 W System.err: at android.security.KeyStore.getKeyStoreException(KeyStore.java:697)
12-07 03:50:17.593 948 1504 W System.err: ... 21 more
12-07 03:50:17.594 948 1504 E JavaBinder: *** Uncaught remote exception! (Exceptions are not yet supported across processes.)
12-07 03:50:17.594 948 1504 E JavaBinder: java.lang.RuntimeException: Failed to decrypt blob
12-07 03:50:17.594 948 1504 E JavaBinder: at com.android.server.locksettings.SyntheticPasswordCrypto.decryptBlob(SyntheticPasswordCrypto.java:129)
12-07 03:50:17.594 948 1504 E JavaBinder: at com.android.server.locksettings.SyntheticPasswordManager.decryptSPBlob(SyntheticPasswordManager.java:1040)
12-07 03:50:17.594 948 1504 E JavaBinder: at com.android.server.locksettings.SyntheticPasswordManager.unwrapSyntheticPasswordBlob(SyntheticPasswordManager.java:906)
12-07 03:50:17.594 948 1504 E JavaBinder: at com.android.server.locksettings.SyntheticPasswordManager.unwrapPasswordBasedSyntheticPassword(SyntheticPasswordManager.java:843)
12-07 03:50:17.594 948 1504 E JavaBinder: at com.android.server.locksettings.LockSettingsService.spBasedDoVerifyCredential(LockSettingsService.java:2105)
12-07 03:50:17.594 948 1504 E JavaBinder: at com.android.server.locksettings.LockSettingsService.doVerifyCredential(LockSettingsService.java:1553)
12-07 03:50:17.594 948 1504 E JavaBinder: at com.android.server.locksettings.LockSettingsService.checkCredential(LockSettingsService.java:1526)
12-07 03:50:17.594 948 1504 E JavaBinder: at com.android.internal.widget.ILockSettings$Stub.onTransact(ILockSettings.java:164)
12-07 03:50:17.594 948 1504 E JavaBinder: at android.os.Binder.execTransact(Binder.java:697)
12-07 03:50:17.594 948 1504 E JavaBinder: Caused by: java.security.InvalidKeyException: Keystore operation failed
12-07 03:50:17.594 948 1504 E JavaBinder: at android.security.KeyStore.getInvalidKeyException(KeyStore.java:760)
12-07 03:50:17.594 948 1504 E JavaBinder: at android.security.KeyStore.getInvalidKeyException(KeyStore.java:781)
12-07 03:50:17.594 948 1504 E JavaBinder: at android.security.keystore.KeyStoreCryptoOperationUtils.getInvalidKeyExceptionForInit(KeyStoreCryptoOperationUtils.java:54)
12-07 03:50:17.594 948 1504 E JavaBinder: at android.security.keystore.KeyStoreCryptoOperationUtils.getExceptionForCipherInit(KeyStoreCryptoOperationUtils.java:89)
12-07 03:50:17.594 948 1504 E JavaBinder: at android.security.keystore.AndroidKeyStoreCipherSpiBase.ensureKeystoreOperationInitialized(AndroidKeyStoreCipherSpiBase.java:265)
12-07 03:50:17.594 948 1504 E JavaBinder: at android.security.keystore.AndroidKeyStoreCipherSpiBase.engineInit(AndroidKeyStoreCipherSpiBase.java:148)
12-07 03:50:17.594 948 1504 E JavaBinder: at javax.crypto.Cipher.tryTransformWithProvider(Cipher.java:2664)
12-07 03:50:17.594 948 1504 E JavaBinder: at javax.crypto.Cipher.tryCombinations(Cipher.java:2575)
12-07 03:50:17.594 948 1504 E JavaBinder: at javax.crypto.Cipher$SpiAndProviderUpdater.updateAndGetSpiAndProvider(Cipher.java:2480)
12-07 03:50:17.594 948 1504 E JavaBinder: at javax.crypto.Cipher.chooseProvider(Cipher.java:567)
12-07 03:50:17.594 948 1504 E JavaBinder: at javax.crypto.Cipher.init(Cipher.java:975)
12-07 03:50:17.594 948 1504 E JavaBinder: at javax.crypto.Cipher.init(Cipher.java:910)
12-07 03:50:17.594 948 1504 E JavaBinder: at com.android.server.locksettings.SyntheticPasswordCrypto.decrypt(SyntheticPasswordCrypto.java:63)
12-07 03:50:17.594 948 1504 E JavaBinder: at com.android.server.locksettings.SyntheticPasswordCrypto.decryptBlob(SyntheticPasswordCrypto.java:122)
12-07 03:50:17.594 948 1504 E JavaBinder: ... 8 more
12-07 03:50:17.594 948 1504 E JavaBinder: Caused by: android.security.KeyStoreException: Signature/MAC verification failed
12-07 03:50:17.594 948 1504 E JavaBinder: at android.security.KeyStore.getKeyStoreException(KeyStore.java:697)
12-07 03:50:17.594 948 1504 E JavaBinder: ... 21 more
--------- beginning of crash
12-07 03:50:17.597 1513 1881 E AndroidRuntime: FATAL EXCEPTION: AsyncTask #1
12-07 03:50:17.597 1513 1881 E AndroidRuntime: Process: com.android.systemui, PID: 1513
12-07 03:50:17.597 1513 1881 E AndroidRuntime: java.lang.RuntimeException: An error occurred while executing doInBackground()
12-07 03:50:17.597 1513 1881 E AndroidRuntime: at android.os.AsyncTask$3.done(AsyncTask.java:353)
12-07 03:50:17.597 1513 1881 E AndroidRuntime: at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:383)
12-07 03:50:17.597 1513 1881 E AndroidRuntime: at java.util.concurrent.FutureTask.setException(FutureTask.java:252)
12-07 03:50:17.597 1513 1881 E AndroidRuntime: at java.util.concurrent.FutureTask.run(FutureTask.java:271)
12-07 03:50:17.597 1513 1881 E AndroidRuntime: at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:245)
12-07 03:50:17.597 1513 1881 E AndroidRuntime: at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1162)
12-07 03:50:17.597 1513 1881 E AndroidRuntime: at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:636)
12-07 03:50:17.597 1513 1881 E AndroidRuntime: at java.lang.Thread.run(Thread.java:764)
12-07 03:50:17.597 1513 1881 E AndroidRuntime: Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'int com.android.internal.widget.VerifyCredentialResponse.getResponseCode()' on a null object reference
12-07 03:50:17.597 1513 1881 E AndroidRuntime: at com.android.internal.widget.LockPatternUtils.checkCredential(LockPatternUtils.java:367)
12-07 03:50:17.597 1513 1881 E AndroidRuntime: at com.android.internal.widget.LockPatternUtils.checkPassword(LockPatternUtils.java:486)
12-07 03:50:17.597 1513 1881 E AndroidRuntime: at com.android.internal.widget.LockPatternChecker$5.doInBackground(LockPatternChecker.java:236)
12-07 03:50:17.597 1513 1881 E AndroidRuntime: at com.android.internal.widget.LockPatternChecker$5.doInBackground(LockPatternChecker.java:233)
12-07 03:50:17.597 1513 1881 E AndroidRuntime: at android.os.AsyncTask$2.call(AsyncTask.java:333)
12-07 03:50:17.597 1513 1881 E AndroidRuntime: at java.util.concurrent.FutureTask.run(FutureTask.java:266)
12-07 03:50:17.597 1513 1881 E AndroidRuntime: ... 4 more

Installed the Express version like I've always done, OTA -> SuperSU -> ElementalX.