# Akka Cassendra Projection Scala 3 Conflicts

**URL:** <https://discuss.akka.io/t/akka-cassendra-projection-scala-3-conflicts/10401>\
**Category:** Persistence / Event Sourcing\
**Created:** [July 18, 2023, 6:42pm UTC](https://discuss.akka.io/t/akka-cassendra-projection-scala-3-conflicts/10401 "2023-07-18T18:42:00Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![smokey](https://avatars.discourse-cdn.com/v4/letter/s/e36b37/32.png) [@smokey](https://discuss.akka.io/u/smokey)\
**Post date:** [July 18, 2023, 6:42pm UTC](https://discuss.akka.io/t/akka-cassendra-projection-scala-3-conflicts/10401/1 "2023-07-18T18:42:00Z")

</div>

I am using scala 3 + akka for event sourcing with the cassandra backend plugin for persistence.  
I want to create projections with akka-projection-cassandra which is a 2.13 library.  
This is a problem since it requires 2.13 for all the other akka libs and compilation fails due to conflicts, but the docs stipulate it (see: [Build a Projection handler • Akka Projection](https://doc.akka.io/docs/akka-projection/current/getting-started/projection-handler.html))

How do I move forward ? Error log below:

libraryDependencies += (“com.lightbend.akka” %% “akka-projection-cassandra” % “1.4.2”).cross(CrossVersion.for3Use2\_13)

```auto
Extracting structure failed: Structure file /tmp/sbt-structure.xml is empty
Modules were resolved with conflicting cross-version suffixes in ProjectRef(uri("file:/home/user1/projects/project1/"), "root"):
com.typesafe.akka:akka-protobuf-v3 _3, _2.13
com.typesafe.akka:akka-actor-typed _3, _2.13
com.typesafe.akka:akka-persistence-query _3, _2.13
com.typesafe.akka:akka-actor _3, _2.13
com.typesafe.akka:akka-persistence _3, _2.13
com.typesafe.akka:akka-stream _3, _2.13
com.lightbend.akka:akka-stream-alpakka-cassandra _3, _2.13
com.lightbend.akka:akka-projection-core _3, _2.13
org.scala-lang.modules:scala-java8-compat _3, _2.13
com.typesafe:ssl-config-core _3, _2.13
com.typesafe.akka:akka-slf4j _3, _2.13
stack trace is suppressed; run last update for the full output
stack trace is suppressed; run last ssExtractDependencies for the full output
(update) Conflicting cross-version suffixes in: com.typesafe.akka:akka-protobuf-v3, com.typesafe.akka:akka-actor-typed, com.typesafe.akka:akka-persistence-query, com.typesafe.akka:akka-actor, com.typesafe.akka:akka-persistence, com.typesafe.akka:akka-stream, com.lightbend.akka:akka-stream-alpakka-cassandra, com.lightbend.akka:akka-projection-core, org.scala-lang.modules:scala-java8-compat, com.typesafe:ssl-config-core, com.typesafe.akka:akka-slf4j
(ssExtractDependencies) Conflicting cross-version suffixes in: com.typesafe.akka:akka-protobuf-v3, com.typesafe.akka:akka-actor-typed, com.typesafe.akka:akka-persistence-query, com.typesafe.akka:akka-actor, com.typesafe.akka:akka-persistence, com.typesafe.akka:akka-stream, com.lightbend.akka:akka-stream-alpakka-cassandra, com.lightbend.akka:akka-projection-core, org.scala-lang.modules:scala-java8-compat, com.typesafe:ssl-config-core, com.typesafe.akka:akka-slf4j
Total time: 0 s, completed 18 Jul 2023

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