Error: java.util.concurrent.ExecutionException: java.lang.IllegalStateException: Unknown transaction in Blazegraph

Question

I am running below SPARQL query to delete some triples from blazegraph (from UPDATE tab).

DELETE {
graph <http://example.org/mapping> {

  ?s ?b ?c
} 
  }
where
{

graph <http://example.org/mapping> {
?s ?b ?c

FILTER (strstarts(str(?s), 'https://www.omim.org/entry/')) 
}

}

However, I get below error while running above query.

ERROR: SPARQL-UPDATE: updateStr=DELETE {
graph  {

  ?s ?b ?c
} 
  }
where
{
graph  {
?s ?b ?c
FILTER (strstarts(str(?s), 'https://www.omim.org/entry/')) 
}
}
java.util.concurrent.ExecutionException: java.lang.IllegalStateException: Unknown transaction
    at java.util.concurrent.FutureTask.report(FutureTask.java:122)
    at java.util.concurrent.FutureTask.get(FutureTask.java:192)
    at com.bigdata.rdf.sail.webapp.BigdataServlet.submitApiTask(BigdataServlet.java:294)
    at com.bigdata.rdf.sail.webapp.QueryServlet.doSparqlUpdate(QueryServlet.java:460)
    at com.bigdata.rdf.sail.webapp.QueryServlet.doPost(QueryServlet.java:241)
    at com.bigdata.rdf.sail.webapp.RESTServlet.doPost(RESTServlet.java:269)
    at com.bigdata.rdf.sail.webapp.MultiTenancyServlet.doPost(MultiTenancyServlet.java:195)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:707)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
    at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:865)
    at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:535)
    at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:146)
    at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:548)
    at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:132)
    at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:257)
    at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:1595)
    at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:255)
    at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1340)
...............

What exactly is the issue with this query? Any help is highly appreciated.