This is a fresh installation 7.9. My engine server and application server are s

...kougar-driver.jar:]
at com.appiancorp.kougar.mapper.Mapper.request(Mapper.java:63) [appian-kougar-mapper.jar:]
at com.appiancorp.kougar.services.KougarServiceInvocationHandler$KInvocationHandler.invoke(KougarServiceInvocationHandler.java:178) [appian-kougar-mapper.jar:]
at com.appiancorp.kougar.services.KougarServiceInvocationHandler$KougarMethodInvocation.proceed(KougarServiceInvocationHandler.java:270) [appian-kougar-mapper.jar:]
at com.appiancorp.security.authz.AuthorizationMethodInterceptor.invoke(AuthorizationMethodInterceptor.java:54) [appian-security.jar:]
at com.appiancorp.kougar.services.KougarServiceInvocationHandler.invoke(KougarServiceInvocationHandler.java:307) [appian-kougar-mapper.jar:]
at com.sun.proxy.$Proxy70.getCredentials(Unknown Source)
at com.appiancorp.ag.GroupServiceJavaImpl.getCredentials(GroupServiceJavaImpl.java:551) [appian-ag.jar:]
at com.appiancorp.ag.GroupServiceJavaImpl.g...

...etCachedCredentials(GroupServiceJavaImpl.java:577) [appian-ag.jar:]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) [rt.jar:1.8.0_45]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) [rt.jar:1.8.0_45]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) [rt.jar:1.8.0_45]
at java.lang.reflect.Method.invoke(Method.java:497) [rt.jar:1.8.0_45]
at com.appiancorp.kougar.services.KougarServiceInvocationHandler$JavaInvocationHandler.invoke(KougarServiceInvocationHandler.java:104) [appian-kougar-mapper.jar:]
at com.appiancorp.kougar.services.KougarServiceInvocationHandler$KougarMethodInvocation.proceed(KougarServiceInvocationHandler.java:270) [appian-kougar-mapper.jar:]
at com.appiancorp.security.authz.AuthorizationMethodInterceptor.invoke(AuthorizationMethodInterceptor.java:54) [appian-security.jar:]
at com.appiancorp.kougar.serv...

... ices.KougarServiceInvocationHandler.invoke(KougarServiceInvocationHandler.java:307) [appian-kougar-mapper.jar:]
at com.sun.proxy.$Proxy70.getCachedCredentials(Unknown Source)
at com.appiancorp.services.AbstractServiceContext.getCredentials(AbstractServiceContext.java:236) [appian-suiteapi.jar:]
at com.appiancorp.services.AbstractServiceContext.getKougarCredentials(AbstractServiceContext.java:225) [appian-suiteapi.jar:]
at com.appiancorp.kougar.services.KougarServiceInvocationHandler$KInvocationHandler.invoke(KougarServiceInvocationHandler.java:147) [appian-kougar-mapper.jar:]
at com.appiancorp.kougar.services.KougarServiceInvocationHandler$KougarMethodInvocation.proceed(KougarServiceInvocationHandler.java:270) [appian-kougar-mapper.jar:]
at com.appiancorp.security.authz.AuthorizationMethodInterceptor.invoke(AuthorizationMethodInterceptor.java:54) [appian-security.jar:]
at com.appiancorp.kougar.services.KougarS...

... erviceInvocationHandler.invoke(KougarServiceInvocationHandler.java:307) [appian-kougar-mapper.jar:]
at com.sun.proxy.$Proxy72.getIdByUuid(Unknown Source)
at com.appiancorp.common.initialize.MigrationFlag.<clinit>(MigrationFlag.java:32) [appian-common.jar:]
... 19 more

Have you applied any hotfix to this installation? Please check that the appian-topology.xml file is properly uncommented.

see documentation here: forum.appian.com/.../Post-Install_Configurations.html

This is my appian-topology.xml configuration:
<topology port="5000">
<server host="hqbpm01">
<engine name="forums"/>
<engine name="notify"/>
<engine name="notify-email"/>
<engine name="channels"/>
<engine name="content"/>
<engine name="collaboration-statistics"/>
<engine name="personalization"/>
<engine name="portal"/>
<engine name="metadata"/>
<engine name="process-design"/>
<engine name="process-analytics0"/>
<engine name="process-analytics1"/>
<engine name="process-analytics2"/>
<engine name="process-execution0"/>
<engine name="process-execution1"/>
<engine name="process-execution2"/>
</server>
<search-cluster port="9300">
<search-server/>
</search-cluster>
</topology>


The engine is up:
_APP_ _ACTIVE_GW_ _STATUS_ _ISSUES_
Discussion Forums 1/1 Okay

Notifications Service 1/1 Okay

Notifications Email Processor 1/1 Okay

Channels 1/1 Okay

Collaboration 1/1 Okay

Collaboration Statistics 1/1 Okay

Personalization 1/1 Okay

Portal 1/1 Okay

Metadata Structure Service 1/1 Okay

Process-Design 1/1 Okay

Process-Analytics0000 1/1 Okay

Process-Analytics0001 1/1 Okay

Process-Analytics0002 1/1 Okay

Process-Exec00 1/1 Okay

Process-Exec01 1/1 Okay

Process-Exec02 1/1 Okay

But I still got the same error after re-installing Appian and Jboss

problem was fixed. the engine server and the application server were using different appian.sec file.