I am implementing datastore for the first time in my app but I have this error showing up onm all complex class

incompatible types: NonExistentClass cannot be converted to Annotation

the .proto file looks like this:

syntax = "proto3";

option java_package = "com.myapp.app";
option java_multiple_files = true;

message LastBackup {
    bool valid = 1;
    string time = 2;
    bool enabled  = 3;
    int64 id = 4;
    CustomData data = 5;
}

message CustomData {
    int32 id = 1;
    repeated CustomItem items = 2;
}

message CustomItem {
    string name = 4;
    string image = 5;
}

the error is basically happening on all complex message : CustomData and CustomItem

I tried to rename them using My just to make a difference and see if the error could come from a duplicate message but the message still appear.

The reason I renamed them is because, CustomData is also a kotlin data class defined to handle the Json response from a server.

So overall goal was to backup in the protobuf datastore Json response. The app is having a data class named Backup.kt which contain:

data class Backup(
    val valid: Boolean,
    val time : String,
    val enable: Boolean,
    val id : Long,
    val data: CustomData
)

data class CustomData (
  val id: int,
  val items: List<CustomItem>
)

data class CustomItem (
  val name: String,
  val image: String
)

So I create a proto file as defined above.

Then I also got the issue :

jetified-protobuf-java-4.26.0 (com.google.protobuf:protobuf-java:4.26.0) and jetified-protobuf-javalite-3.19.4 (com.google.protobuf:protobuf-javalite:3.19.4)

and my gradle look like this:

plugins {
    id 'kotlinx-serialization'
    id "com.google.protobuf" version "0.8.17"
}

dependencies {
    implementation "androidx.datastore:datastore:1.1.0"
    implementation "com.google.protobuf:protobuf-javalite:3.21.11"
plugins {
    id 'kotlinx-serialization'
    id "com.google.protobuf" version "0.8.17"
}

dependencies {
    implementation "androidx.datastore:datastore:1.1.0"
    implementation "com.google.protobuf:protobuf-javalite:3.19.4"
    //implementation "com.google.protobuf:protobuf-kotlin-lite:3.21.11"
}

protobuf {
    protoc {
        artifact = "com.google.protobuf:protoc:3.19.4"
    }

    // Generates the java Protobuf-lite code for the Protobufs in this project. See
    // https://github.com/google/protobuf-gradle-plugin#customizing-protobuf-compilation
    // for more information.
    generateProtoTasks {
        all().each { task ->
            task.builtins {
                java {
                    option 'lite'
                }
               // kotlin {
               //     option 'lite'
               // }
            }
        }
    }
}
}

protobuf {
    protoc {
        artifact = "com.google.protobuf:protoc:3.21.11"
    }

    // Generates the java Protobuf-lite code for the Protobufs in this project. See
    // https://github.com/google/protobuf-gradle-plugin#customizing-protobuf-compilation
    // for more information.
    generateProtoTasks {
        all().each { task ->
            task.builtins {
                java {
                    option 'lite'
                }
                //kotlin {
                //    option 'lite'
                //}
            }
        }
    }
}

Any idea why the issue is happeneing ?

• Is it because the proto message have the same name that the data class ?
• something else ?

Thanls