org.tmatesoft.svn.core.SVNException: svn: Unknown error

java.lang.NullPointerException: 	at java.io.FileInputStream.(FileInputStream.java:103)	at org.tmatesoft.svn.core.auth.SVNSSLAuthentication.(SVNSSLAuthentication.java:46)	at org.tmatesoft.svn.core.internal.wc.DefaultSVNAuthenticationManager$PersistentAuthenticationProvider.requestClientAuthentication(DefaultSVNAuthenticationManager.java:502)	at org.tmatesoft.svn.core.internal.wc.DefaultSVNAuthenticationManager.getFirstAuthentication(DefaultSVNAuthenticationManager.java:159)	at org.tmatesoft.svn.core.internal.io.dav.http.HTTPSSLKeyManager.initialize(HTTPSSLKeyManager.java:255)	at org.tmatesoft.svn.core.internal.io.dav.http.HTTPSSLKeyManager.initializeNoException(HTTPSSLKeyManager.java:237)	at org.tmatesoft.svn.core.internal.io.dav.http.HTTPSSLKeyManager.chooseClientAlias(HTTPSSLKeyManager.java:131)	at com.sun.net.ssl.internal.ssl.AbstractWrapper.chooseClientAlias(SSLContextImpl.java:262)	at com.sun.net.ssl.internal.ssl.ClientHandshaker.serverHelloDone(ClientHandshaker.java:500)	at com.sun.net.ssl.internal.ssl.ClientHandshaker.processMessage(ClientHandshaker.java:197)	at com.sun.net.ssl.internal.ssl.Handshaker.processLoop(Handshaker.java:516)	at com.sun.net.ssl.internal.ssl.Handshaker.process_record(Handshaker.java:454)	at com.sun.net.ssl.internal.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:884)	at com.sun.net.ssl.internal.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1096)	at com.sun.net.ssl.internal.ssl.SSLSocketImpl.writeRecord(SSLSocketImpl.java:623)	at com.sun.net.ssl.internal.ssl.AppOutputStream.write(AppOutputStream.java:59)	at java.io.BufferedOutputStream.flushBuffer(BufferedOutputStream.java:65)	at java.io.BufferedOutputStream.flush(BufferedOutputStream.java:123)	at org.tmatesoft.svn.core.internal.io.dav.http.HTTPConnection.sendData(HTTPConnection.java:226)	at org.tmatesoft.svn.core.internal.io.dav.http.HTTPRequest.dispatch(HTTPRequest.java:166)	at org.tmatesoft.svn.core.internal.io.dav.http.HTTPConnection.request(HTTPConnection.java:345)	at org.tmatesoft.svn.core.internal.io.dav.http.HTTPConnection.request(HTTPConnection.java:273)	at org.tmatesoft.svn.core.internal.io.dav.http.HTTPConnection.request(HTTPConnection.java:261)	at org.tmatesoft.svn.core.internal.io.dav.DAVConnection.exchangeCapabilities(DAVConnection.java:516)	at org.tmatesoft.svn.core.internal.io.dav.DAVConnection.open(DAVConnection.java:98)	at org.tmatesoft.svn.core.internal.io.dav.DAVRepository.openConnection(DAVRepository.java:1001)	at org.tmatesoft.svn.core.internal.io.dav.DAVRepository.getLatestRevision(DAVRepository.java:178)	at org.tmatesoft.svn.core.wc.SVNBasicClient.getRevisionNumber(SVNBasicClient.java:482)	at org.tmatesoft.svn.core.wc.SVNBasicClient.getLocations(SVNBasicClient.java:851)	at org.tmatesoft.svn.core.wc.SVNBasicClient.createRepository(SVNBasicClient.java:534)	at org.tmatesoft.svn.core.wc.SVNUpdateClient.doCheckout(SVNUpdateClient.java:893)	at hudson.scm.SubversionSCM$CheckOutTask.invoke(SubversionSCM.java:673)	at hudson.scm.SubversionSCM$CheckOutTask.invoke(SubversionSCM.java:593)	at hudson.FilePath.act(FilePath.java:676)	at hudson.FilePath.act(FilePath.java:660)	at hudson.scm.SubversionSCM.checkout(SubversionSCM.java:586)	at hudson.scm.SubversionSCM.checkout(SubversionSCM.java:534)	at hudson.model.AbstractProject.checkout(AbstractProject.java:1011)	at hudson.model.AbstractBuild$AbstractRunner.checkout(AbstractBuild.java:485)	at hudson.model.AbstractBuild$AbstractRunner.run(AbstractBuild.java:411)	at hudson.model.Run.run(Run.java:1193)	at hudson.model.FreeStyleBuild.run(FreeStyleBuild.java:46)	at hudson.model.ResourceController.execute(ResourceController.java:88)	at hudson.model.Executor.run(Executor.java:122)