diff --git a/api/worker.go b/api/worker.go
index f59fa4bf..a6a2f304 100644
--- a/api/worker.go
+++ b/api/worker.go
@@ -174,6 +174,9 @@ func (w *Worker) GetTransaction(txid string, spendingTxs bool) (*Tx, error) {
 		valOutSat.Add(&valOutSat, &bchainVout.ValueSat)
 		vout.ScriptPubKey.Hex = bchainVout.ScriptPubKey.Hex
 		vout.ScriptPubKey.AddrDesc, vout.ScriptPubKey.Addresses, vout.ScriptPubKey.Searchable, err = w.getAddressesFromVout(bchainVout)
+		if err != nil {
+			glog.Errorf("getAddressesFromVout error %v, %v, output %v", err, vout.ScriptPubKey.AddrDesc, vout.N)
+		}
 		if ta != nil {
 			vout.Spent = ta.Outputs[i].Spent
 			if spendingTxs && vout.Spent {
@@ -363,6 +366,9 @@ func (w *Worker) GetAddress(address string, page int, txsOnPage int, onlyTxids b
 	}
 	// convert the address to the format defined by the parser
 	addresses, _, err := w.chainParser.GetAddressesFromAddrDesc(addrDesc)
+	if err != nil {
+		return nil, errors.Annotatef(err, "GetAddressesFromAddrDesc %v", addrDesc)
+	}
 	if len(addresses) == 1 {
 		address = addresses[0]
 	}
@@ -505,10 +511,15 @@ func (w *Worker) GetBlock(bid string, page int, txsOnPage int) (*Block, error) {
 	if page < 0 {
 		page = 0
 	}
+	// try to decide if passed string (bid) is block height or block hash
+	// if it's a number, must be less than int32
 	var hash string
 	height, err := strconv.Atoi(bid)
 	if err == nil && height < int(^uint32(0)) {
 		hash, err = w.db.GetBlockHash(uint32(height))
+		if err != nil {
+			hash = bid
+		}
 	} else {
 		hash = bid
 	}
diff --git a/bchain/coins/bch/bcashparser.go b/bchain/coins/bch/bcashparser.go
index 83411081..d0d48730 100644
--- a/bchain/coins/bch/bcashparser.go
+++ b/bchain/coins/bch/bcashparser.go
@@ -91,7 +91,6 @@ func GetChainParams(chain string) *chaincfg.Params {
 			panic(err)
 		}
 	}
-	var params *chaincfg.Params
 	switch chain {
 	case "test":
 		return &TestNetParams
@@ -100,8 +99,6 @@ func GetChainParams(chain string) *chaincfg.Params {
 	default:
 		return &MainNetParams
 	}
-
-	return params
 }
 
 // GetAddrDescFromAddress returns internal address representation of given address
diff --git a/bchain/coins/eth/ethrpc.go b/bchain/coins/eth/ethrpc.go
index ffdac499..8a5c98c9 100644
--- a/bchain/coins/eth/ethrpc.go
+++ b/bchain/coins/eth/ethrpc.go
@@ -416,6 +416,9 @@ func (b *EthereumRPC) GetBlock(hash string, height uint32) (*bchain.Block, error
 		return nil, errors.Annotatef(fmt.Errorf("server returned empty transaction list but block header indicates transactions"), "hash %v, height %v", hash, height)
 	}
 	bbh, err := b.ethHeaderToBlockHeader(head)
+	if err != nil {
+		return nil, errors.Annotatef(err, "hash %v, height %v", hash, height)
+	}
 	// TODO - this is probably not the correct size
 	bbh.Size = len(raw)
 	btxs := make([]bchain.Tx, len(body.Transactions))
diff --git a/bchain/coins/grs/grsparser.go b/bchain/coins/grs/grsparser.go
index 460eadc9..9c560b63 100644
--- a/bchain/coins/grs/grsparser.go
+++ b/bchain/coins/grs/grsparser.go
@@ -66,15 +66,12 @@ func GetChainParams(chain string) *chaincfg.Params {
 			panic(err)
 		}
 	}
-	var params *chaincfg.Params
 	switch chain {
 	case "test":
 		return &TestNetParams
 	default:
 		return &MainNetParams
 	}
-
-	return params
 }
 
 // PackTx packs transaction to byte array using protobuf
diff --git a/bchain/coins/zec/zcashparser.go b/bchain/coins/zec/zcashparser.go
index 51093c1b..f2b2c5e9 100644
--- a/bchain/coins/zec/zcashparser.go
+++ b/bchain/coins/zec/zcashparser.go
@@ -71,7 +71,6 @@ func GetChainParams(chain string) *chaincfg.Params {
 			panic(err)
 		}
 	}
-	var params *chaincfg.Params
 	switch chain {
 	case "test":
 		return &TestNetParams
@@ -80,8 +79,6 @@ func GetChainParams(chain string) *chaincfg.Params {
 	default:
 		return &MainNetParams
 	}
-
-	return params
 }
 
 // PackTx packs transaction to byte array using protobuf
diff --git a/server/internal.go b/server/internal.go
index 5e12dcf1..6ef09f1e 100644
--- a/server/internal.go
+++ b/server/internal.go
@@ -82,9 +82,17 @@ func (s *InternalServer) Shutdown(ctx context.Context) error {
 
 func (s *InternalServer) index(w http.ResponseWriter, r *http.Request) {
 	si, err := s.api.GetSystemInfo(true)
+	if err != nil {
+		glog.Error(err)
+		w.WriteHeader(http.StatusInternalServerError)
+		return
+	}
 	buf, err := json.MarshalIndent(si, "", "    ")
 	if err != nil {
 		glog.Error(err)
+		w.WriteHeader(http.StatusInternalServerError)
+		return
 	}
+
 	w.Write(buf)
 }