Created attachment 1459726 [details]
engine log

Description of problem:
After trying to delete fence agent (through RESTApi) I get an NPE, also happens for adding a fence agent afterwards.

Version-Release number of selected component (if applicable):
ovirt-engine-4.2.5.1-0.1.el7ev.noarch
eap7-wildfly-7.1.3-2.GA_redhat_2.1.ep7.el7.noarch

How reproducible:
always

Steps to Reproduce:
1. add fence agent with RESTApi
2. remove fence agent with RESTApi
3. add again

Actual results:
Internal server error and NPE in log

Expected results:
all actions working correctly

Additional info:
2018-07-18 17:06:42,759+03 ERROR [org.ovirt.engine.core.bll.AddFenceAgentCommand] (default task-9) [agents_create_39fb2012-841c-4b62]
Command 'org.ovirt.engine.core.bll.AddFenceAgentCommand' failed: null
2018-07-18 17:06:42,759+03 ERROR [org.ovirt.engine.core.bll.AddFenceAgentCommand] (default task-9) [agents_create_39fb2012-841c-4b62]
Exception: java.lang.NullPointerException
        at org.ovirt.engine.core.common.businessentities.pm.FenceAgent.toString(FenceAgent.java:207) [common.jar:]
        at org.ovirt.engine.core.bll.CommandBase.getCommandParamatersString(CommandBase.java:1203) [bll.jar:]
        at org.ovirt.engine.core.bll.CommandBase.logRunningCommand(CommandBase.java:1224) [bll.jar:]
        at org.ovirt.engine.core.bll.CommandBase.executeWithoutTransaction(CommandBase.java:1132) [bll.jar:]
        at org.ovirt.engine.core.bll.CommandBase.executeActionInTransactionScope(CommandBase.java:1285) [bll.jar:]
        at org.ovirt.engine.core.bll.CommandBase.runInTransaction(CommandBase.java:1934) [bll.jar:]
        at org.ovirt.engine.core.utils.transaction.TransactionSupport.executeInNewTransaction(TransactionSupport.java:202) [utils.jar:
]
        at org.ovirt.engine.core.utils.transaction.TransactionSupport.executeInRequired(TransactionSupport.java:137) [utils.jar:]
        at org.ovirt.engine.core.utils.transaction.TransactionSupport.executeInScope(TransactionSupport.java:105) [utils.jar:]
        at org.ovirt.engine.core.bll.CommandBase.execute(CommandBase.java:1345) [bll.jar:]
        at org.ovirt.engine.core.bll.CommandBase.executeAction(CommandBase.java:400) [bll.jar:]
        at org.ovirt.engine.core.bll.executor.DefaultBackendActionExecutor.execute(DefaultBackendActionExecutor.java:13) [bll.jar:]
        at org.ovirt.engine.core.bll.Backend.runAction(Backend.java:468) [bll.jar:]
        at org.ovirt.engine.core.bll.Backend.runActionImpl(Backend.java:450) [bll.jar:]
        at org.ovirt.engine.core.bll.Backend.runAction(Backend.java:403) [bll.jar:]
        at sun.reflect.GeneratedMethodAccessor621.invoke(Unknown Source) [:1.8.0_171]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) [rt.jar:1.8.0_171]
        at java.lang.reflect.Method.invoke(Method.java:498) [rt.jar:1.8.0_171]
        at org.jboss.as.ee.component.ManagedReferenceMethodInterceptor.processInvocation(ManagedReferenceMethodInterceptor.java:52)
        at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:422)
        at org.jboss.invocation.InterceptorContext$Invocation.proceed(InterceptorContext.java:509)
... this goes on for a bit ...
        at io.undertow.servlet.handlers.ServletInitialHandler.dispatchRequest(ServletInitialHandler.java:272)
        at io.undertow.servlet.handlers.ServletInitialHandler.access$000(ServletInitialHandler.java:81)
        at io.undertow.servlet.handlers.ServletInitialHandler$1.handleRequest(ServletInitialHandler.java:104)
        at io.undertow.server.Connectors.executeRootHandler(Connectors.java:330)
        at io.undertow.server.HttpServerExchange$1.run(HttpServerExchange.java:812)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [rt.jar:1.8.0_171]
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [rt.jar:1.8.0_171]
        at java.lang.Thread.run(Thread.java:748) [rt.jar:1.8.0_171]