WebLogic Admin Server Startup Fails.

JPS-01538: The default policy provider was not found
JPS-01514: The default context is missing in jps-config.xml.
JPS-04301: Cannot read from policy store
<Jun 22, 2016 12:19:11 AM PDT> <Error> <Security> <BEA-090892> <The dynamic loading of the OPSS java security policy provider class oracle.security.jps.internal.policystore.JavaPolicyProvider failed due to problem inside OPSS java security policy provider. Exception was thrown when loading or setting the JPSS policy provider. Enable the debug flag -Djava.security.debug=jpspolicy to get more information. Error message: JPS-01538: The default policy provider was not found.>
<Jun 22, 2016 12:19:11 AM PDT> <Critical> <WebLogicServer> <BEA-000386> <Server subsystem failed. Reason: weblogic.security.SecurityInitializationException: The dynamic loading of the OPSS java security policy provider class oracle.security.jps.internal.policystore.JavaPolicyProvider failed due to problem inside OPSS java security policy provider. Exception was thrown when loading or setting the JPSS policy provider. Enable the debug flag -Djava.security.debug=jpspolicy to get more information. Error message: JPS-01538: The default policy provider was not found.
weblogic.security.SecurityInitializationException: The dynamic loading of the OPSS java security policy provider class oracle.security.jps.internal.policystore.JavaPolicyProvider failed due to problem inside OPSS java security policy provider. Exception was thrown when loading or setting the JPSS policy provider. Enable the debug flag -Djava.security.debug=jpspolicy to get more information. Error message: JPS-01538: The default policy provider was not found.
at weblogic.security.service.CommonSecurityServiceManagerDelegateImpl.loadOPSSPolicy(CommonSecurityServiceManagerDelegateImpl.java:1394)
at weblogic.security.service.CommonSecurityServiceManagerDelegateImpl.initialize(CommonSecurityServiceManagerDelegateImpl.java:1018)
at weblogic.security.service.SecurityServiceManager.initialize(SecurityServiceManager.java:875)
at weblogic.security.SecurityService.start(SecurityService.java:141)
at weblogic.t3.srvr.SubsystemRequest.run(SubsystemRequest.java:64)
Truncated. see log file for complete stacktrace
Caused By: oracle.security.jps.JpsRuntimeException: JPS-01538: The default policy provider was not found.
at oracle.security.jps.internal.policystore.PolicyDelegationController.<init>(PolicyDelegationController.java:273)
at oracle.security.jps.internal.policystore.PolicyDelegationController.<init>(PolicyDelegationController.java:265)
at oracle.security.jps.internal.policystore.JavaPolicyProvider.<init>(JavaPolicyProvider.java:136)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
Truncated. see log file for complete stacktrace
Caused By: oracle.security.jps.JpsException: JPS-01538: The default policy provider was not found.
at oracle.security.jps.internal.policystore.PolicyUtil.getDefaultPolicyStore(PolicyUtil.java:705)
at oracle.security.jps.internal.policystore.PolicyDelegationController.<init>(PolicyDelegationController.java:271)
at oracle.security.jps.internal.policystore.PolicyDelegationController.<init>(PolicyDelegationController.java:265)
at oracle.security.jps.internal.policystore.JavaPolicyProvider.<init>(JavaPolicyProvider.java:136)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
Truncated. see log file for complete stacktrace
Caused By: oracle.security.jps.JpsException: JPS-01514: The default context is missing in jps-config.xml.
at oracle.security.jps.internal.policystore.PolicyUtil$1.run(PolicyUtil.java:665)
at oracle.security.jps.internal.policystore.PolicyUtil$1.run(PolicyUtil.java:650)
at java.security.AccessController.doPrivileged(Native Method)
at oracle.security.jps.internal.policystore.PolicyUtil.getDefaultPolicyStore(PolicyUtil.java:650)
at oracle.security.jps.internal.policystore.PolicyDelegationController.<init>(PolicyDelegationController.java:271)
Truncated. see log file for complete stacktrace
Caused By: oracle.security.jps.JpsRuntimeException: JPS-04301: Cannot read from policy store.
at oracle.security.jps.internal.policystore.xml.XmlPolicyStore.buildFromFile(XmlPolicyStore.java:298)
at oracle.security.jps.internal.policystore.xml.XmlPolicyStore.<init>(XmlPolicyStore.java:177)
at oracle.security.jps.internal.policystore.xml.XmlPolicyStoreProvider.getInstance(XmlPolicyStoreProvider.java:106)
at oracle.security.jps.internal.policystore.xml.XmlPolicyStoreProvider.getInstance(XmlPolicyStoreProvider.java:76)
at oracle.security.jps.internal.core.runtime.ContextFactoryImpl.findServiceInstance(ContextFactoryImpl.java:139)
SOLUTION
Delete the pki*.lck files present under /tmp folder and restart Admin Server
Note: Verify the TEMP folder used by Weblogic and look for the lock files under that folder, as it may not be /tmp always