Clojure exception while trying to execute a send

send-error

java.util.concurrent.RejectedExecutionException
        at java.util.concurrent.ThreadPoolExecutor$AbortPolicy.rejectedExecution(ThreadPoolExecutor.java:1768)
        at java.util.concurrent.ThreadPoolExecutor.reject(ThreadPoolExecutor.java:767)
        at java.util.concurrent.ThreadPoolExecutor.execute(ThreadPoolExecutor.java:658)
        at clojure.lang.Agent$Action.execute(Agent.java:75)
        at clojure.lang.Agent.enqueue(Agent.java:255)
        at clojure.lang.Agent.dispatchAction(Agent.java:242)
        at clojure.lang.Agent.dispatch(Agent.java:228)
        at clojure.core$send.doInvoke(core.clj:1591)
        at clojure.lang.RestFn.invoke(RestFn.java:426)
        at scheduler$eval3501$run_job__3692.invoke(NO_SOURCE_FILE:1)
        at scheduler$make_dbus_proxy$fn__1759.invoke(scheduler.clj:288)
        at scheduler.proxy$java.lang.Object$Scheduler$9a8af07c.runJob(Unknown Source)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:597)
        at org.freedesktop.dbus.AbstractConnection$1.run(Unknown Source)
        at org.freedesktop.dbus.AbstractConnection$_workerthread.run(Unknown Source)