BigIP HTTP500 on collections in /mgmt/ltm

Hello,

I am running a F5 BigIP on "BIG-IP 13.1.1.2 Build 0.0.4 Point Release 2". I want to query ressources by REST, which works fine for single ressources, e.g.:

I can ask /mgmt/tm/ltm/virtual/<id> without any problems with HTTP GET, but when I query the collection by asking /mgmt/tm/ltm/ i get an HTTP500 with the following error in log:  

WARNING][277904][22 May 2019 07:41:35 UTC][8100/mgmt/shared/resolver/groups ForwarderPassThroughWorker] URI:http://localhost:8100/mgmt/tm/ltm/virtual, Referrer: myip..., Method:GET, Exception:java.util.concurrent.TimeoutException: remoteSender:10.2.107.29, method:GET
 
        at com.f5.rest.common.RestWorker.logAndFailExpiredOperation(RestWorker.java:3099)
 
        at com.f5.rest.common.RestWorker.checkForExpiredOperations(RestWorker.java:3088)
 
        at com.f5.rest.common.RestServer.checkAndExpirePendingWorkerOperations(RestServer.java:1457)
 
        at com.f5.rest.common.RestServer.access$400(RestServer.java:48)
 
        at com.f5.rest.common.RestServer$4.run(RestServer.java:1430)
 
        at com.f5.rest.common.ScheduleTaskManager$2$1.run(ScheduleTaskManager.java:123)
 
        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:473)
 
        at java.util.concurrent.FutureTask.run(FutureTask.java:262)
 
        at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:178)
 
        at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:292)
 
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1152)
 
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:622)
 
        at java.lang.Thread.run(Thread.java:748)

The same problem applies to the /mgmt/ltm/pool ressource. 

Can anyone help me here?

Thanks and regards;)