'Unknown index type for Index' errors with record-layer examples code. (maven)

Using Layers
1

I have been scratching my head here trying to figure out what the problem is for quite a long time now, any kind of help would be amazing.

I’ve been trying to setup the examples code on the public repo using maven instead of gradle, and for some reason anything to do with secondary indexes always throws an exception.

com.apple.foundationdb.record.metadata.MetaDataException: Unknown index type for Index {'Customer$phone_number'}#2
        at com.apple.foundationdb.record.provider.foundationdb.IndexMaintainerRegistryImpl.getIndexValidator(IndexMaintainerRegistryImpl.java:81) ~
        at com.apple.foundationdb.record.metadata.MetaDataValidator.validateIndex(MetaDataValidator.java:118) ~
        at java.util.ArrayList.forEach(ArrayList.java:1511) ~[?:?]
        at com.apple.foundationdb.record.metadata.MetaDataValidator.validateCurrentAndFormerIndexes(MetaDataValidator.java:104)
        at com.apple.foundationdb.record.metadata.MetaDataValidator.validate(MetaDataValidator.java:65) ~
        at com.apple.foundationdb.record.RecordMetaDataBuilder.build(RecordMetaDataBuilder.java:1395) ~
        at com.apple.foundationdb.record.RecordMetaDataBuilder.build(RecordMetaDataBuilder.java:1348) ~
        at com.apple.foundationdb.record.RecordMetaDataBuilder.getRecordMetaData(RecordMetaDataBuilder.java:1337) ~
        at com.apple.foundationdb.record.RecordMetaData.build(RecordMetaData.java:487) ~

Commenting out the secondary in-line single field indexes on protobuf allows the rest of the example code to run fine (reading/writing to the db + logging these changes), until new indexes are added and rebuilt - at that point the program crashes again.

com.apple.foundationdb.record.metadata.MetaDataException: Unknown index type for Index {'email_address'}#2
        at com.apple.foundationdb.record.provider.foundationdb.IndexMaintainerRegistryImpl.getIndexValidator(IndexMaintainerRegistryImpl.java:81) ~
        at com.apple.foundationdb.record.metadata.MetaDataValidator.validateIndex(MetaDataValidator.java:118) ~
        at java.util.ArrayList.forEach(ArrayList.java:1511) ~[?:?]
        at com.apple.foundationdb.record.metadata.MetaDataValidator.validateCurrentAndFormerIndexes(MetaDataValidator.java:104) ~
        at com.apple.foundationdb.record.metadata.MetaDataValidator.validate(MetaDataValidator.java:65) ~
        at com.apple.foundationdb.record.RecordMetaDataBuilder.build(RecordMetaDataBuilder.java:1395) ~
        at com.apple.foundationdb.record.RecordMetaDataBuilder.build(RecordMetaDataBuilder.java:1348) ~
        at com.apple.foundationdb.record.RecordMetaDataBuilder.getRecordMetaData(RecordMetaDataBuilder.java:1337) ~

Maven dependencies:

        <dependency>
            <groupId>org.foundationdb</groupId>
            <artifactId>fdb-java</artifactId>
            <version>6.3.23</version>
        </dependency>
        <dependency>
            <groupId>org.foundationdb</groupId>
            <artifactId>fdb-record-layer-core-pb3</artifactId>
            <version>3.1.228.0</version>
        </dependency>
        <dependency>
            <groupId>com.google.protobuf</groupId>
            <artifactId>protobuf-java</artifactId>
            <version>3.19.3</version>
        </dependency>

Maven repositories:

        <repository>
            <id>fdb-record-layer</id>
            <url>https://ossartifacts.jfrog.io/artifactory/fdb-record-layer/</url>
        </repository>

Maven plugins:

            <plugin>
                <groupId>com.github.os72</groupId>
                <artifactId>protoc-jar-maven-plugin</artifactId>
                <version>3.11.4</version>
                <executions>
                    <execution>
                        <phase>generate-sources</phase>
                        <goals>
                            <goal>run</goal>
                        </goals>
                        <configuration>
                            <protocArtifact>com.google.protobuf:protoc:3.6.1</protocArtifact>
                            <addProtoSources>all</addProtoSources>
                            <includeMavenTypes>direct</includeMavenTypes>
                            <inputDirectories>
                                <include>src/main/protobuf</include>
                            </inputDirectories>
                        </configuration>
                    </execution>
                </executions>
            </plugin>

Building metadata with build(false) to skip validations results in a segfault.

Any help will be much appreciated, thanks.