Hitting /solr// ends up with HttpSolrCall NPE when using Solr Cloud

  "error":{
    "trace":"java.lang.NullPointerException\n\tat org.apache.solr.servlet.HttpSolrCall.getCoreUrl(HttpSolrCall.java:1047)\n\tat org.apache.solr.servlet.HttpSolrCall.getRemoteCoreUrl(HttpSolrCall.java:1021)\n\tat org.apache.solr.servlet.HttpSolrCall.extractRemotePath(HttpSolrCall.java:428)\n\tat org.apache.solr.servlet.HttpSolrCall.init(HttpSolrCall.java:293)\n\tat org.apache.solr.servlet.HttpSolrCall.call(HttpSolrCall.java:522)\n\tat org.apache.solr.servlet.SolrDispatchFilter.doFilter(SolrDispatchFilter.java:427)\n\tat org.apache.solr.servlet.SolrDispatchFilter.doFilter(SolrDispatchFilter.java:357)\n\tat org.eclipse.jetty.servlet.FilterHolder.doFilter(FilterHolder.java:201)\n\tat org.eclipse.jetty.servlet.ServletHandler$Chain.doFilter(ServletHandler.java:1601)\n\tat org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:548)\n\tat org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:143)\n\tat org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:600)\n\tat org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:127)\n\tat org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:235)\n\tat org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:1624)\n\tat org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:233)\n\tat org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1434)\n\tat org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:188)\n\tat org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:501)\n\tat org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:1594)\n\tat org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:186)\n\tat org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1349)\n\tat org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141)\n\tat org.eclipse.jetty.server.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:191)\n\tat org.eclipse.jetty.server.handler.HandlerCollection.handle(HandlerCollection.java:146)\n\tat org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:127)\n\tat org.eclipse.jetty.rewrite.handler.RewriteHandler.handle(RewriteHandler.java:322)\n\tat org.eclipse.jetty.server.handler.gzip.GzipHandler.handle(GzipHandler.java:763)\n\tat org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:127)\n\tat org.eclipse.jetty.server.Server.handle(Server.java:516)\n\tat org.eclipse.jetty.server.HttpChannel.lambda$handle$1(HttpChannel.java:400)\n\tat org.eclipse.jetty.server.HttpChannel.dispatch(HttpChannel.java:645)\n\tat org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:392)\n\tat org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:277)\n\tat org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:311)\n\tat org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:105)\n\tat org.eclipse.jetty.io.ChannelEndPoint$1.run(ChannelEndPoint.java:104)\n\tat org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.runTask(EatWhatYouKill.java:338)\n\tat org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.doProduce(EatWhatYouKill.java:315)\n\tat org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.tryProduce(EatWhatYouKill.java:173)\n\tat org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.run(EatWhatYouKill.java:131)\n\tat org.eclipse.jetty.util.thread.ReservedThreadExecutor$ReservedThread.run(ReservedThreadExecutor.java:409)\n\tat org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:883)\n\tat org.eclipse.jetty.util.thread.QueuedThreadPool$Runner.run(QueuedThreadPool.java:1034)\n\tat java.base/java.lang.Thread.run(Unknown Source)\n",
    "code":500}}