diff --git a/ibft/controller/controller_sync.go b/ibft/controller/controller_sync.go
index fd70b9f39f..759941c20e 100644
--- a/ibft/controller/controller_sync.go
+++ b/ibft/controller/controller_sync.go
@@ -36,6 +36,14 @@ func (i *Controller) processSyncQueueMessages() {
 func (i *Controller) ProcessSyncMessage(msg *network.SyncChanObj) {
 	var lastChangeRoundMsg *proto.SignedMessage
 	currentInstaceSeqNumber := int64(-1)
+	if i.currentInstance != nil {
+		if i.currentInstance.State() == nil {
+			i.logger.Warn("ProcessSyncMessage: i.currentInstance != nil but i.currentInstance.State() == nil")
+		} else if i.currentInstance.State().SeqNumber == nil {
+			i.logger.Warn("ProcessSyncMessage: i.currentInstance != nil && i.currentInstance.State() != nil " +
+				"but i.currentInstance.State().SeqNumber == nil")
+		}
+	}
 	if i.currentInstance != nil && i.currentInstance.State() != nil && i.currentInstance.State().SeqNumber != nil {
 		lastChangeRoundMsg = i.currentInstance.GetLastChangeRoundMsg()
 		currentInstaceSeqNumber = int64(i.currentInstance.State().SeqNumber.Get())