diff --git a/core/parentchain/block-importer/src/block_importer.rs b/core/parentchain/block-importer/src/block_importer.rs
index d93c19f38e..785e72be30 100644
--- a/core/parentchain/block-importer/src/block_importer.rs
+++ b/core/parentchain/block-importer/src/block_importer.rs
@@ -33,9 +33,9 @@ use itp_types::{
 use log::*;
 use sp_runtime::{
 	generic::SignedBlock as SignedBlockG,
-	traits::{Block as ParentchainBlockTrait, NumberFor},
+	traits::{Block as ParentchainBlockTrait, Header as HeaderT, NumberFor},
 };
-use std::{marker::PhantomData, sync::Arc, vec::Vec};
+use std::{marker::PhantomData, sync::Arc, vec, vec::Vec};
 
 /// Parentchain block import implementation.
 pub struct ParentchainBlockImporter<
@@ -117,15 +117,25 @@ impl<
 		let mut calls = Vec::<OpaqueCall>::new();
 		let id = self.validator_accessor.parentchain_id();
 
-		debug!("[{:?}] Import blocks to light-client!", id);
+		debug!(
+			"[{:?}] Import {} blocks to light-client. event blocks {}",
+			id,
+			blocks_to_import.len(),
+			events_to_import.len()
+		);
+		let events_to_import_aligned: Vec<Vec<u8>> = if events_to_import.is_empty() {
+			vec![vec![]; blocks_to_import.len()]
+		} else {
+			events_to_import
+		};
 		for (signed_block, raw_events) in
-			blocks_to_import.into_iter().zip(events_to_import.into_iter())
+			blocks_to_import.into_iter().zip(events_to_import_aligned.into_iter())
 		{
 			if let Err(e) = self
 				.validator_accessor
 				.execute_mut_on_validator(|v| v.submit_block(&signed_block))
 			{
-				error!("[{:?}] Header submission to light client failed: {:?}", id, e);
+				error!("[{:?}] Header submission to light client failed for block number {} and hash {:?}: {:?}", id, signed_block.block.header().number(), signed_block.block.hash(), e);
 
 				return Err(e.into())
 			}
diff --git a/core/parentchain/light-client/src/light_validation.rs b/core/parentchain/light-client/src/light_validation.rs
index 5da9db71d6..37d41ba757 100644
--- a/core/parentchain/light-client/src/light_validation.rs
+++ b/core/parentchain/light-client/src/light_validation.rs
@@ -26,6 +26,7 @@ use core::iter::Iterator;
 use itp_ocall_api::EnclaveOnChainOCallApi;
 use itp_storage::{Error as StorageError, StorageProof, StorageProofChecker};
 use itp_types::parentchain::{IdentifyParentchain, ParentchainId};
+use log::error;
 use sp_runtime::{
 	generic::SignedBlock,
 	traits::{Block as ParentchainBlockTrait, Header as HeaderTrait},
@@ -145,6 +146,13 @@ where
 		let relay = self.light_validation_state.get_relay_mut();
 
 		if relay.last_finalized_block_header.hash() != *header.parent_hash() {
+			error!("header ancestry mismatch! last imported was block nr {:?} with hash {:?}, attempting to import nr {:?} with hash {:?} and ancestor {:?}",
+				relay.last_finalized_block_header.number(),
+				relay.last_finalized_block_header.hash(),
+				header.number(),
+				header.hash(),
+				header.parent_hash()
+			);
 			return Err(Error::HeaderAncestryMismatch)
 		}
 
diff --git a/enclave-runtime/src/lib.rs b/enclave-runtime/src/lib.rs
index 4a4c6f2d16..d055baaf9d 100644
--- a/enclave-runtime/src/lib.rs
+++ b/enclave-runtime/src/lib.rs
@@ -564,6 +564,7 @@ pub unsafe extern "C" fn sync_parentchain(
 		immediate_import == 1,
 	) {
 		error!("Error synching parentchain: {:?}", e);
+		return sgx_status_t::SGX_ERROR_UNEXPECTED
 	}
 
 	sgx_status_t::SGX_SUCCESS
diff --git a/service/src/main_impl.rs b/service/src/main_impl.rs
index 1436576d7f..26a4732aa0 100644
--- a/service/src/main_impl.rs
+++ b/service/src/main_impl.rs
@@ -513,7 +513,7 @@ fn start_worker<E, T, D, InitializationHandler, WorkerModeProvider>(
 						);
 						info!("The primary worker enclave is {:?}", primary_enclave);
 						if enclave.get_shard_creation_header(shard).is_err() {
-							//obtain provisioning from last active worker
+							//obtain provisioning from last active worker as this hasn't been done before
 							info!("my state doesn't know the creation header of the shard. will request provisioning");
 							sync_state::sync_state::<_, _, WorkerModeProvider>(
 								&integritee_rpc_api,
@@ -533,6 +533,7 @@ fn start_worker<E, T, D, InitializationHandler, WorkerModeProvider>(
 			},
 			None => {
 				println!("We are the primary worker on this shard and the shard is untouched. Will initialize it");
+				enclave.init_shard(shard.encode()).unwrap();
 				enclave
 					.init_shard_creation_parentchain_header(
 						shard,
diff --git a/service/src/parentchain_handler.rs b/service/src/parentchain_handler.rs
index dc1841f9d1..2680297f2a 100644
--- a/service/src/parentchain_handler.rs
+++ b/service/src/parentchain_handler.rs
@@ -196,7 +196,12 @@ where
 				until_synced_header.number + 1,
 				min(until_synced_header.number + BLOCK_SYNC_BATCH_SIZE, curr_block_number),
 			)?;
-			info!("[{:?}] Found {} block(s) to sync in this chunk", id, block_chunk_to_sync.len());
+			info!(
+				"[{:?}] Found {} block(s) to sync in this chunk. immediate import={} ",
+				id,
+				block_chunk_to_sync.len(),
+				immediate_import
+			);
 			if block_chunk_to_sync.is_empty() {
 				return Ok(until_synced_header)
 			}
@@ -252,7 +257,7 @@ where
 				.ok_or(Error::EmptyChunk)?;
 			info!(
 				"[{:?}] Synced {} out of {} finalized parentchain blocks",
-				id, until_synced_header.number, curr_block_number,
+				id, api_client_until_synced_header.number, curr_block_number,
 			);
 
 			// #TODO: #1451: fix api/client types