Metaspace problem play 2.7

Unfortunately I am getting this frequently when I try to compile

[error] Error while emitting StudentDAO.scala
[error] Metaspace
[error] ## Exception when compiling 103 sources to /mnt/important/webAppDeveloping/edu-assistant/target/scala-2.13/classes
[error] Metaspace
[error] 
[error]            
[error] a.a.ActorSystemImpl - Internal server error, sending 500 response
akka.http.impl.util.One2OneBidiFlow$OutputTruncationException: Inner flow was completed without producing result elements for 1 outstanding elements
        at akka.http.impl.util.One2OneBidiFlow$OutputTruncationException$.apply(One2OneBidiFlow.scala:22)
        at akka.http.impl.util.One2OneBidiFlow$OutputTruncationException$.apply(One2OneBidiFlow.scala:22)
        at akka.http.impl.util.One2OneBidiFlow$One2OneBidi$$anon$1$$anon$4.onUpstreamFinish(One2OneBidiFlow.scala:97)
        at akka.stream.impl.fusing.GraphInterpreter.processEvent(GraphInterpreter.scala:506)
        at akka.stream.impl.fusing.GraphInterpreter.execute(GraphInterpreter.scala:376)
        at akka.stream.impl.fusing.GraphInterpreterShell.runBatch(ActorGraphInterpreter.scala:606)
        at akka.stream.impl.fusing.GraphInterpreterShell$AsyncInput.execute(ActorGraphInterpreter.scala:485)
        at akka.stream.impl.fusing.GraphInterpreterShell.processEvent(ActorGraphInterpreter.scala:581)
        at akka.stream.impl.fusing.ActorGraphInterpreter.akka$stream$impl$fusing$ActorGraphInterpreter$$processEvent(ActorGraphInterpreter.scala:749)
        at akka.stream.impl.fusing.ActorGraphInterpreter$$anonfun$receive$1.applyOrElse(ActorGraphInterpreter.scala:764)

The akka-http server backend sometimes swallows error messages…
For now, can you switch to the Netty Server Backend and try again? It might give you a clearer error message.
In you build.sbt just enable the plugin (and disable akka-http):

lazy val root = ...enablePlugins(PlayNettyServer).disablePlugins(PlayAkkaHttpServer)

Ok, I am checking according to your suggestion.

@mkurz, thanks till now I have not got any java.lang.OutOfMemoryError: Metaspace