solution: upgrade to the latest api definitions

build.gradle

@@ -37,8 +37,10 @@ group = 'io.emeraldpay.dshackle'
 //    x.x-SNAPSHOT for development
 version = '0.9.0-SNAPSHOT'
 
-targetCompatibility = '11'
-sourceCompatibility = '11'
+java {
+    sourceCompatibility = JavaVersion.VERSION_11
+    targetCompatibility = JavaVersion.VERSION_11
+}
 
 repositories {
     mavenLocal()
@@ -57,7 +59,7 @@ configurations {
 }
 
 dependencies {
-    implementation "io.emeraldpay:emerald-api:0.8.0"
+    implementation "io.emeraldpay:emerald-api:0.9.0"
 
     implementation "io.grpc:grpc-protobuf:${grpcVersion}"
     implementation "io.grpc:grpc-stub:${grpcVersion}"
@@ -82,7 +84,7 @@ dependencies {
     implementation "io.projectreactor.netty:reactor-netty:0.9.7.RELEASE"
     implementation 'io.projectreactor.addons:reactor-extra:3.3.3.RELEASE'
     implementation 'io.projectreactor.kotlin:reactor-kotlin-extensions:1.0.2.RELEASE'
-    implementation 'com.salesforce.servicelibs:reactor-grpc:0.10.0'
+    implementation "com.salesforce.servicelibs:reactor-grpc:$reactiveGrpcVersion"
     implementation 'io.lettuce:lettuce-core:5.2.2.RELEASE'
 
     implementation "io.infinitape:etherjar-domain:$etherjarVersion"

gradle.properties

@@ -1,12 +1,12 @@
 # Languages
 groovyVersion=2.5.5
 kotlinVersion=1.3.11
-protocVersion=3.7.1
+protocVersion=3.9.0
 # Main Libs
 slf4jVersion=1.7.25
 jacksonVersion=2.11.0
-grpcVersion=1.25.0
-protobufVersion=3.7.1
+grpcVersion=1.32.1
+reactiveGrpcVersion=1.0.1
 springBootVersion=2.1.14.RELEASE
 springVersion=5.2.6.RELEASE
 springSecurtyVersion=5.3.2.RELEASE

src/main/kotlin/io/emeraldpay/dshackle/rpc/TrackBitcoinAddress.kt

@@ -28,6 +28,7 @@ import io.emeraldpay.dshackle.upstream.bitcoin.BitcoinMultistream
 import io.emeraldpay.dshackle.upstream.bitcoin.data.SimpleUnspent
 import io.emeraldpay.dshackle.upstream.grpc.BitcoinGrpcUpstream
 import io.emeraldpay.grpc.Chain
+import org.apache.commons.lang3.StringUtils
 import org.bitcoinj.params.MainNetParams
 import org.bitcoinj.params.TestNet3Params
 import org.slf4j.LoggerFactory
@@ -101,10 +102,10 @@ class TrackBitcoinAddress(
                         ?: return Flux.error(IllegalStateException("Xpub verification is not available"))
 
                 val addressXpub = request.address.addressXpub
-                if (!addressXpub.xpub.isValidUtf8) {
-                    return Flux.error(IllegalArgumentException("Invalid xpub string"))
+                if (StringUtils.isEmpty(addressXpub.xpub)) {
+                    return Flux.error(IllegalArgumentException("xpub string is empty"))
                 }
-                val xpub = addressXpub.xpub.toStringUtf8()
+                val xpub = addressXpub.xpub
                 val start = Math.max(0, addressXpub.start).toInt()
                 val limit = Math.min(100, Math.max(1, addressXpub.limit)).toInt()
                 xpubAddresses.activeAddresses(xpub, start, limit)
@@ -197,12 +198,26 @@ class TrackBitcoinAddress(
         val chain = Chain.byId(request.asset.chainValue)
         val upstream = multistreamHolder.getUpstream(chain)?.cast(BitcoinMultistream::class.java)
                 ?: return Flux.error(SilentException.UnsupportedBlockchain(request.asset.chainValue))
+        println("call get balance")
         return if (isBalanceAvailable(chain)) {
             val addresses = allAddresses(upstream, request)
             requestBalances(chain, upstream, addresses, request.includeUtxo)
                     .map(this@TrackBitcoinAddress::buildResponse)
+                    .doOnError { t ->
+                        log.error("Failed to get balance", t)
+                    }
         } else {
+            println("call remote balance")
             getRemoteBalance(upstream, request)
+                    .doOnEach {
+                        println("each ${it.type}")
+                    }
+                    .doOnError { t ->
+                        t.printStackTrace()
+                    }
+                    .doOnComplete {
+                        println("received all")
+                    }
         }
     }