diff --git a/pkg/core/native/management.go b/pkg/core/native/management.go
index b28357537..8fef66d93 100644
--- a/pkg/core/native/management.go
+++ b/pkg/core/native/management.go
@@ -64,7 +64,7 @@ func newManagement() *Management {
 	}
 
 	desc := newDescriptor("getContract", smartcontract.ArrayType,
-		manifest.NewParameter("hash", smartcontract.Hash160Type))
+		manifest.NewParameter("hash", smartcontract.ByteArrayType))
 	md := newMethodAndPrice(m.getContract, 1000000, smartcontract.ReadStates)
 	m.AddMethod(md, desc)
 
@@ -357,11 +357,11 @@ func (m *Management) getMinimumDeploymentFee(ic *interop.Context, args []stackit
 
 // GetMinimumDeploymentFee returns the minimum required fee for contract deploy.
 func (m *Management) GetMinimumDeploymentFee(dao dao.DAO) int64 {
-	return getInt64WithKey(m.ContractID, dao, keyMinimumDeploymentFee, defaultMinimumDeploymentFee)
+	return int64(getUint32WithKey(m.ContractID, dao, keyMinimumDeploymentFee, defaultMinimumDeploymentFee))
 }
 
 func (m *Management) setMinimumDeploymentFee(ic *interop.Context, args []stackitem.Item) stackitem.Item {
-	value := toBigInt(args[0]).Int64()
+	value := toUint32(args[0])
 	if value < 0 {
 		panic(fmt.Errorf("MinimumDeploymentFee cannot be negative"))
 	}
@@ -372,7 +372,7 @@ func (m *Management) setMinimumDeploymentFee(ic *interop.Context, args []stackit
 	if !ok {
 		return stackitem.NewBool(false)
 	}
-	err = setInt64WithKey(m.ContractID, ic.DAO, keyMinimumDeploymentFee, value)
+	err = setUint32WithKey(m.ContractID, ic.DAO, keyMinimumDeploymentFee, value)
 	if err != nil {
 		panic(err)
 	}
@@ -483,7 +483,7 @@ func (m *Management) PostPersist(ic *interop.Context) error {
 
 // Initialize implements Contract interface.
 func (m *Management) Initialize(ic *interop.Context) error {
-	return setInt64WithKey(m.ContractID, ic.DAO, keyMinimumDeploymentFee, defaultMinimumDeploymentFee)
+	return setUint32WithKey(m.ContractID, ic.DAO, keyMinimumDeploymentFee, defaultMinimumDeploymentFee)
 }
 
 // PutContractState saves given contract state into given DAO.
diff --git a/pkg/core/native/native_neo.go b/pkg/core/native/native_neo.go
index 739264680..00f654c36 100644
--- a/pkg/core/native/native_neo.go
+++ b/pkg/core/native/native_neo.go
@@ -108,24 +108,24 @@ func newNEO() *NEO {
 	n.committeeHash.Store(util.Uint160{})
 
 	desc := newDescriptor("unclaimedGas", smartcontract.IntegerType,
-		manifest.NewParameter("account", smartcontract.Hash160Type),
+		manifest.NewParameter("account", smartcontract.ByteArrayType),
 		manifest.NewParameter("end", smartcontract.IntegerType))
 	md := newMethodAndPrice(n.unclaimedGas, 3000000, smartcontract.ReadStates)
 	n.AddMethod(md, desc)
 
 	desc = newDescriptor("registerCandidate", smartcontract.BoolType,
-		manifest.NewParameter("pubkey", smartcontract.PublicKeyType))
+		manifest.NewParameter("pubkey", smartcontract.ByteArrayType))
 	md = newMethodAndPrice(n.registerCandidate, 5000000, smartcontract.WriteStates)
 	n.AddMethod(md, desc)
 
 	desc = newDescriptor("unregisterCandidate", smartcontract.BoolType,
-		manifest.NewParameter("pubkey", smartcontract.PublicKeyType))
+		manifest.NewParameter("pubkey", smartcontract.ByteArrayType))
 	md = newMethodAndPrice(n.unregisterCandidate, 5000000, smartcontract.WriteStates)
 	n.AddMethod(md, desc)
 
 	desc = newDescriptor("vote", smartcontract.BoolType,
-		manifest.NewParameter("account", smartcontract.Hash160Type),
-		manifest.NewParameter("pubkey", smartcontract.PublicKeyType))
+		manifest.NewParameter("account", smartcontract.ByteArrayType),
+		manifest.NewParameter("pubkey", smartcontract.ByteArrayType))
 	md = newMethodAndPrice(n.vote, 5000000, smartcontract.WriteStates)
 	n.AddMethod(md, desc)
 
@@ -246,11 +246,9 @@ func (n *NEO) updateCommittee(ic *interop.Context) error {
 		return ic.DAO.PutStorageItem(n.ContractID, prefixCommittee, si)
 	}
 
-	committee, cvs, err := n.computeCommitteeMembers(ic.Chain, ic.DAO)
+	_, cvs, err := n.computeCommitteeMembers(ic.Chain, ic.DAO)
 	if err != nil {
 		return err
-	} else if cvs == nil {
-		cvs = toKeysWithVotes(committee)
 	}
 	if err := n.updateCache(cvs, ic.Chain); err != nil {
 		return err
@@ -852,18 +850,28 @@ func (n *NEO) computeCommitteeMembers(bc blockchainer.Blockchainer, d dao.DAO) (
 	// votersCount / totalSupply must be >= 0.2
 	votersCount.Mul(votersCount, big.NewInt(effectiveVoterTurnout))
 	voterTurnout := votersCount.Div(votersCount, n.getTotalSupply(d))
-	if voterTurnout.Sign() != 1 {
-		pubs := bc.GetStandByCommittee()
-		return pubs, nil, nil
-	}
+
+	sbVals := bc.GetStandByCommittee()
+	count := len(sbVals)
 	cs, err := n.getCandidates(d, false)
 	if err != nil {
 		return nil, nil, err
 	}
-	sbVals := bc.GetStandByCommittee()
-	count := len(sbVals)
-	if len(cs) < count {
-		return sbVals, nil, nil
+	if voterTurnout.Sign() != 1 || len(cs) < count {
+		kvs := make(keysWithVotes, count)
+		for i := range kvs {
+			kvs[i].UnmarshaledKey = sbVals[i]
+			kvs[i].Key = string(sbVals[i].Bytes())
+			votes := big.NewInt(0)
+			for j := range cs {
+				if cs[j].Key == kvs[i].Key {
+					votes = cs[j].Votes
+					break
+				}
+			}
+			kvs[i].Votes = votes
+		}
+		return sbVals, kvs, nil
 	}
 	pubs := make(keys.PublicKeys, count)
 	for i := range pubs {
diff --git a/pkg/core/native/native_nep17.go b/pkg/core/native/native_nep17.go
index cfb2cf7cd..cf23f2549 100644
--- a/pkg/core/native/native_nep17.go
+++ b/pkg/core/native/native_nep17.go
@@ -59,22 +59,23 @@ func newNEP17Native(name string) *nep17TokenNative {
 	n.AddMethod(md, desc)
 
 	desc = newDescriptor("balanceOf", smartcontract.IntegerType,
-		manifest.NewParameter("account", smartcontract.Hash160Type))
+		manifest.NewParameter("account", smartcontract.ByteArrayType))
 	md = newMethodAndPrice(n.balanceOf, 1000000, smartcontract.ReadStates)
 	n.AddMethod(md, desc)
 
-	transferParams := []manifest.Parameter{
-		manifest.NewParameter("from", smartcontract.Hash160Type),
-		manifest.NewParameter("to", smartcontract.Hash160Type),
-		manifest.NewParameter("amount", smartcontract.IntegerType),
-	}
 	desc = newDescriptor("transfer", smartcontract.BoolType,
-		append(transferParams, manifest.NewParameter("data", smartcontract.AnyType))...,
+		manifest.NewParameter("from", smartcontract.ByteArrayType),
+		manifest.NewParameter("to", smartcontract.ByteArrayType),
+		manifest.NewParameter("amount", smartcontract.IntegerType),
+		manifest.NewParameter("data", smartcontract.AnyType),
 	)
 	md = newMethodAndPrice(n.Transfer, 9000000, smartcontract.WriteStates|smartcontract.AllowCall|smartcontract.AllowNotify)
 	n.AddMethod(md, desc)
 
-	n.AddEvent("Transfer", transferParams...)
+	n.AddEvent("Transfer",
+		manifest.NewParameter("from", smartcontract.Hash160Type),
+		manifest.NewParameter("to", smartcontract.Hash160Type),
+		manifest.NewParameter("amount", smartcontract.IntegerType))
 
 	return n
 }
diff --git a/pkg/core/native/policy.go b/pkg/core/native/policy.go
index 3c7411315..90f4ced7b 100644
--- a/pkg/core/native/policy.go
+++ b/pkg/core/native/policy.go
@@ -97,7 +97,7 @@ func newPolicy() *Policy {
 	p.AddMethod(md, desc)
 
 	desc = newDescriptor("isBlocked", smartcontract.BoolType,
-		manifest.NewParameter("account", smartcontract.Hash160Type))
+		manifest.NewParameter("account", smartcontract.ByteArrayType))
 	md = newMethodAndPrice(p.isBlocked, 1000000, smartcontract.ReadStates)
 	p.AddMethod(md, desc)
 
@@ -144,12 +144,12 @@ func newPolicy() *Policy {
 	p.AddMethod(md, desc)
 
 	desc = newDescriptor("blockAccount", smartcontract.BoolType,
-		manifest.NewParameter("account", smartcontract.Hash160Type))
+		manifest.NewParameter("account", smartcontract.ByteArrayType))
 	md = newMethodAndPrice(p.blockAccount, 3000000, smartcontract.WriteStates)
 	p.AddMethod(md, desc)
 
 	desc = newDescriptor("unblockAccount", smartcontract.BoolType,
-		manifest.NewParameter("account", smartcontract.Hash160Type))
+		manifest.NewParameter("account", smartcontract.ByteArrayType))
 	md = newMethodAndPrice(p.unblockAccount, 3000000, smartcontract.WriteStates)
 	p.AddMethod(md, desc)
 
diff --git a/pkg/rpc/server/server.go b/pkg/rpc/server/server.go
index f960395f9..1c6565b95 100644
--- a/pkg/rpc/server/server.go
+++ b/pkg/rpc/server/server.go
@@ -539,7 +539,11 @@ func (s *Server) getApplicationLog(reqParams request.Params) (interface{}, *resp
 
 	trig := trigger.All
 	if len(reqParams) > 1 {
-		trig, err = trigger.FromString(reqParams.ValueWithType(1, request.StringT).String())
+		trigString := reqParams.ValueWithType(1, request.StringT)
+		if trigString == nil {
+			return nil, response.ErrInvalidParams
+		}
+		trig, err = trigger.FromString(trigString.String())
 		if err != nil {
 			return nil, response.ErrInvalidParams
 		}
diff --git a/pkg/rpc/server/server_test.go b/pkg/rpc/server/server_test.go
index f1bf8384d..22c47b757 100644
--- a/pkg/rpc/server/server_test.go
+++ b/pkg/rpc/server/server_test.go
@@ -121,6 +121,11 @@ var rpcTestCases = map[string][]rpcTestCase{
 				assert.Equal(t, vm.HaltState, res.Executions[0].VMState)
 			},
 		},
+		{
+			name:   "invalid trigger (not a string)",
+			params: `["` + genesisBlockHash + `", 1]`,
+			fail:   true,
+		},
 		{
 			name:   "no params",
 			params: `[]`,