Onboarding: puzzles

[mtvec]

I've seeded the puzzle database as described here but when trying to open /training, I get the following error:

[error] reactivemongo.api.Cursor - Fails to send request
reactivemongo.core.errors.DatabaseException$$anon$1: DatabaseException['Unrecognized pipeline stage name: '$replaceWith'' (code = 40324)]
[error] l.app.http.ErrorHandler - 

! @7k1mige2p - Internal server error, for (GET) [/training] ->
 
play.api.http.HttpErrorHandlerExceptions$$anon$1: Execution exception[[: DatabaseException['Unrecognized pipeline stage name: '$replaceWith'' (code = 40324)]]]
        at play.api.http.HttpErrorHandlerExceptions$.throwableToUsefulException(HttpErrorHandler.scala:327)
        at play.api.http.DefaultHttpErrorHandler.onServerError(HttpErrorHandler.scala:246)
        at play.core.server.AkkaHttpServer$$anonfun$2.applyOrElse(AkkaHttpServer.scala:399)
        at play.core.server.AkkaHttpServer$$anonfun$2.applyOrElse(AkkaHttpServer.scala:391)
        at scala.concurrent.impl.Promise$Transformation.run(Promise.scala:454)
        at akka.dispatch.TaskInvocation.run(AbstractDispatcher.scala:48)
        at akka.dispatch.ForkJoinExecutorConfigurator$AkkaForkJoinTask.exec(ForkJoinExecutorConfigurator.scala:48)
        at java.base/java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:290)
        at java.base/java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(ForkJoinPool.java:1020)
        at java.base/java.util.concurrent.ForkJoinPool.scan(ForkJoinPool.java:1656)
Caused by: reactivemongo.core.errors.DatabaseException$$anon$1: DatabaseException['Unrecognized pipeline stage name: '$replaceWith'' (code = 40324)]
[error] http - ERROR 500 Puzzle.home
play.api.http.HttpErrorHandlerExceptions$$anon$1: Execution exception[[: DatabaseException['Unrecognized pipeline stage name: '$replaceWith'' (code = 40324)]]]
        at play.api.http.HttpErrorHandlerExceptions$.throwableToUsefulException(HttpErrorHandler.scala:327)
        at play.api.http.DefaultHttpErrorHandler.onServerError(HttpErrorHandler.scala:246)
        at play.core.server.AkkaHttpServer$$anonfun$2.applyOrElse(AkkaHttpServer.scala:399)
        at play.core.server.AkkaHttpServer$$anonfun$2.applyOrElse(AkkaHttpServer.scala:391)
        at scala.concurrent.impl.Promise$Transformation.run(Promise.scala:454)
        at akka.dispatch.TaskInvocation.run(AbstractDispatcher.scala:48)
        at akka.dispatch.ForkJoinExecutorConfigurator$AkkaForkJoinTask.exec(ForkJoinExecutorConfigurator.scala:48)
        at java.base/java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:290)
        at java.base/java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(ForkJoinPool.java:1020)
        at java.base/java.util.concurrent.ForkJoinPool.scan(ForkJoinPool.java:1656)
Caused by: reactivemongo.core.errors.DatabaseException$$anon$1: DatabaseException['Unrecognized pipeline stage name: '$replaceWith'' (code = 40324)]

I get the same error on /storm and /racer but /streak works.

Any idea what might be causing this issue?

[niklasf]

What's your MongoDB version?

$replaceWith was introduced in MongoDB 4.2, so at least that is required. Will update the onboarding guide. Our own servers are running on 4.4.5.

[mtvec]

Thanks, I was running an older version of MongoDB (3.6.9, the version in Ubuntu 20.04) and after upgrading to 4.4.6, everything works.