run android demo and to login get error:

04-19 22:24:48.031 7891-10210/com.xmppdemo W/AbstractXMPPConnection: Connection closed with error
javax.net.ssl.SSLHandshakeException: java.security.cert.CertPathValidatorException: Trust anchor for certification path not found.
at com.android.org.conscrypt.OpenSSLSocketImpl.startHandshake(OpenSSLSocketImpl.java:328)
at com.android.org.conscrypt.OpenSSLSocketImpl.waitForHandshake(OpenSSLSocketImpl.java:629)
at com.android.org.conscrypt.OpenSSLSocketImpl.getInputStream(OpenSSLSocketImpl.java:591)
at org.jivesoftware.smack.tcp.XMPPTCPConnection.initReaderAndWriter(XMPPTCPConnection.java:642)
at org.jivesoftware.smack.tcp.XMPPTCPConnection.proceedTLSReceived(XMPPTCPConnection.java:742)
at org.jivesoftware.smack.tcp.XMPPTCPConnection.access$900(XMPPTCPConnection.java:139)
at org.jivesoftware.smack.tcp.XMPPTCPConnection$PacketReader.parsePackets(XMPPTCPConnection.java:1003)
at org.jivesoftware.smack.tcp.XMPPTCPConnection$PacketReader.access$200(XMPPTCPConnection.java:937)
at org.jivesoftware.smack.tcp.XMPPTCPConnection$PacketReader$1.run(XMPPTCPConnection.java:952)
at java.lang.Thread.run(Thread.java:833)
Caused by: java.security.cert.CertificateException: java.security.cert.CertPathValidatorException: Trust anchor for certification path not found.
at com.android.org.conscrypt.TrustManagerImpl.checkTrusted(TrustManagerImpl.java:324)
at com.android.org.conscrypt.TrustManagerImpl.checkServerTrusted(TrustManagerImpl.java:225)
at com.android.org.conscrypt.Platform.checkServerTrusted(Platform.java:115)
at com.android.org.conscrypt.OpenSSLSocketImpl.verifyCertificateChain(OpenSSLSocketImpl.java:556)
at com.android.org.conscrypt.NativeCrypto.SSL_do_handshake(Native Method)
at com.android.org.conscrypt.OpenSSLSocketImpl.startHandshake(OpenSSLSocketImpl.java:324)
at com.android.org.conscrypt.OpenSSLSocketImpl.waitForHandshake(OpenSSLSocketImpl.java:629) 
at com.android.org.conscrypt.OpenSSLSocketImpl.getInputStream(OpenSSLSocketImpl.java:591) 
at org.jivesoftware.smack.tcp.XMPPTCPConnection.initReaderAndWriter(XMPPTCPConnection.java:642) 
at org.jivesoftware.smack.tcp.XMPPTCPConnection.proceedTLSReceived(XMPPTCPConnection.java:742) 
at org.jivesoftware.smack.tcp.XMPPTCPConnection.access$900(XMPPTCPConnection.java:139) 
at org.jivesoftware.smack.tcp.XMPPTCPConnection$PacketReader.parsePackets(XMPPTCPConnection.java:1003) 
at org.jivesoftware.smack.tcp.XMPPTCPConnection$PacketReader.access$200(XMPPTCPConnection.java:937) 
at org.jivesoftware.smack.tcp.XMPPTCPConnection$PacketReader$1.run(XMPPTCPConnection.java:952) 
at java.lang.Thread.run(Thread.java:833) 
Caused by: java.security.cert.CertPathValidatorException: Trust anchor for certification path not found.
at com.android.org.conscrypt.TrustManagerImpl.checkTrusted(TrustManagerImpl.java:324) 
at com.android.org.conscrypt.TrustManagerImpl.checkServerTrusted(TrustManagerImpl.java:225) 
at com.android.org.conscrypt.Platform.checkServerTrusted(Platform.java:115) 
at com.android.org.conscrypt.OpenSSLSocketImpl.verifyCertificateChain(OpenSSLSocketImpl.java:556) 
at com.android.org.conscrypt.NativeCrypto.SSL_do_handshake(Native Method) 
at com.android.org.conscrypt.OpenSSLSocketImpl.startHandshake(OpenSSLSocketImpl.java:324) 
at com.android.org.conscrypt.OpenSSLSocketImpl.waitForHandshake(OpenSSLSocketImpl.java:629) 
at com.android.org.conscrypt.OpenSSLSocketImpl.getInputStream(OpenSSLSocketImpl.java:591) 
at org.jivesoftware.smack.tcp.XMPPTCPConnection.initReaderAndWriter(XMPPTCPConnection.java:642) 
at org.jivesoftware.smack.tcp.XMPPTCPConnection.proceedTLSReceived(XMPPTCPConnection.java:742) 
at org.jivesoftware.smack.tcp.XMPPTCPConnection.access$900(XMPPTCPConnection.java:139) 
at org.jivesoftware.smack.tcp.XMPPTCPConnection$PacketReader.parsePackets(XMPPTCPConnection.java:1003) 
at org.jivesoftware.smack.tcp.XMPPTCPConnection$PacketReader.access$200(XMPPTCPConnection.java:937) 
at org.jivesoftware.smack.tcp.XMPPTCPConnection$PacketReader$1.run(XMPPTCPConnection.java:952) 
at java.lang.Thread.run(Thread.java:833) 
04-19 22:24:48.034 7891-8071/com.xmppdemo I/ReactNativeJS: react-native-xmpp: Disconnected, error: java.security.cert.CertPathValidatorException: Trust anchor for certification path not found.