I have created one Model and Zeebe Worker using Spring Boot in Java
For Reference
@ZeebeWorker(type = “task1-service-worker”)
public void handleJobFoo() {
// some work
if (!successful) {
// problem shall be indicated to the process:
throw new ZeebeBpmnError(“DOESNT_WORK”, “This does not work because…”);
}
}
But Frequently got following errors 
21:33:49.775 [grpc-default-executor-3] WARN io.camunda.zeebe.client.job.poller - Failed to activate jobs for worker task1Worker#task1Service and job type task1-service-worker
io.grpc.StatusRuntimeException: UNKNOWN
at io.grpc.Status.asRuntimeException(Status.java:533)
at io.grpc.stub.ClientCalls$StreamObserverToCallListenerAdapter.onClose(ClientCalls.java:460)
at io.grpc.internal.ClientCallImpl.closeObserver(ClientCallImpl.java:426)
at io.grpc.internal.ClientCallImpl.access$500(ClientCallImpl.java:66)
at io.grpc.internal.ClientCallImpl$ClientStreamListenerImpl.close(ClientCallImpl.java:689)
at io.grpc.internal.ClientCallImpl$ClientStreamListenerImpl.access$900(ClientCallImpl.java:577)
at io.grpc.internal.ClientCallImpl$ClientStreamListenerImpl$1StreamClosed.runInternal(ClientCallImpl.java:751)
at io.grpc.internal.ClientCallImpl$ClientStreamListenerImpl$1StreamClosed.runInContext(ClientCallImpl.java:740)
at io.grpc.internal.ContextRunnable.run(ContextRunnable.java:37)
at io.grpc.internal.SerializingExecutor.run(SerializingExecutor.java:123)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635)
at java.base/java.lang.Thread.run(Thread.java:833)
Caused by: java.lang.UnsupportedOperationException: null
at io.grpc.netty.AbstractHttp2Headers.setLong(AbstractHttp2Headers.java:465)
at io.grpc.netty.AbstractHttp2Headers.setLong(AbstractHttp2Headers.java:26)
at io.netty.handler.codec.http2.DefaultHttp2ConnectionDecoder$FrameReadListener.onHeadersRead(DefaultHttp2ConnectionDecoder.java:396)
at io.netty.handler.codec.http2.DefaultHttp2ConnectionDecoder$FrameReadListener.onHeadersRead(DefaultHttp2ConnectionDecoder.java:337)
at io.netty.handler.codec.http2.Http2InboundFrameLogger$1.onHeadersRead(Http2InboundFrameLogger.java:56)
at io.netty.handler.codec.http2.DefaultHttp2FrameReader$2.processFragment(DefaultHttp2FrameReader.java:476)
at io.netty.handler.codec.http2.DefaultHttp2FrameReader.readHeadersFrame(DefaultHttp2FrameReader.java:484)
at io.netty.handler.codec.http2.DefaultHttp2FrameReader.processPayloadState(DefaultHttp2FrameReader.java:253)
at io.netty.handler.codec.http2.DefaultHttp2FrameReader.readFrame(DefaultHttp2FrameReader.java:159)
at io.netty.handler.codec.http2.Http2InboundFrameLogger.readFrame(Http2InboundFrameLogger.java:41)
at io.netty.handler.codec.http2.DefaultHttp2ConnectionDecoder.decodeFrame(DefaultHttp2ConnectionDecoder.java:173)
at io.netty.handler.codec.http2.Http2ConnectionHandler$FrameDecoder.decode(Http2ConnectionHandler.java:378)
at io.netty.handler.codec.http2.Http2ConnectionHandler.decode(Http2ConnectionHandler.java:438)
at io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:510)
at io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:449)
at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:279)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357)
at io.netty.handler.ssl.SslHandler.unwrap(SslHandler.java:1372)
at io.netty.handler.ssl.SslHandler.decodeJdkCompatible(SslHandler.java:1235)
at io.netty.handler.ssl.SslHandler.decode(SslHandler.java:1284)
at io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:510)
at io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:449)
at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:279)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357)
at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1410)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:919)
at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:166)
at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:722)
at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:658)
at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:584)
at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:496)
at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:986)
at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
… 1 common frames omitted