diff --git a/extern/sector-storage/ffiwrapper/sealer_cgo.go b/extern/sector-storage/ffiwrapper/sealer_cgo.go
index 92a893437..5783a3547 100644
--- a/extern/sector-storage/ffiwrapper/sealer_cgo.go
+++ b/extern/sector-storage/ffiwrapper/sealer_cgo.go
@@ -10,14 +10,13 @@ import (
 	"crypto/rand"
 	"encoding/base64"
 	"encoding/json"
+	"github.com/ipfs/go-cid"
+	"golang.org/x/xerrors"
 	"io"
 	"math/bits"
 	"os"
 	"runtime"
 
-	"github.com/ipfs/go-cid"
-	"golang.org/x/xerrors"
-
 	ffi "github.com/filecoin-project/filecoin-ffi"
 	rlepluslazy "github.com/filecoin-project/go-bitfield/rle"
 	commcid "github.com/filecoin-project/go-fil-commcid"
diff --git a/extern/sector-storage/manager_post.go b/extern/sector-storage/manager_post.go
index 55b6168e8..2a9cf10bc 100644
--- a/extern/sector-storage/manager_post.go
+++ b/extern/sector-storage/manager_post.go
@@ -134,6 +134,10 @@ func (m *Manager) generateWindowPoSt(ctx context.Context, minerID abi.ActorID, s
 		return nil, nil, xerrors.Errorf("generating fallback challenges: %v", err)
 	}
 
+	sort.Slice(postChallenges.Sectors, func(i, j int) bool {
+		return postChallenges.Sectors[i] < postChallenges.Sectors[j]
+	})
+
 	proofList := make([]ffi.PartitionProof, partitionCount)
 	var wg sync.WaitGroup
 	wg.Add(int(partitionCount))
@@ -162,16 +166,17 @@ func (m *Manager) generateWindowPoSt(ctx context.Context, minerID abi.ActorID, s
 			}
 
 			p, sk, err := m.generatePartitionWindowPost(cctx, spt, ppt, minerID, int(partIdx), sectors, randomness)
-			if len(sk) > 0 {
-				log.Errorf("generateWindowPost part:%d, skipped:%d, err: %+v", partIdx, len(sk), err)
+			if err != nil || len(sk) > 0 {
+				log.Errorf("generateWindowPost part:%d, skipped:%d, sectors: %d, err: %+v", partIdx, len(sk), len(sectors), err)
 				flk.Lock()
 				skipped = append(skipped, sk...)
+
+				if err != nil {
+					retErr = multierror.Append(retErr, xerrors.Errorf("partitionCount:%d err:%+v", partIdx, err))
+					return
+				}
 				flk.Unlock()
 			}
-			if err != nil {
-				retErr = multierror.Append(retErr, xerrors.Errorf("partitionCount:%d err:%+v", partIdx, err))
-				return
-			}
 
 			proofList[partIdx] = ffi.PartitionProof(p)
 		}(partIdx)
diff --git a/extern/sector-storage/worker_local.go b/extern/sector-storage/worker_local.go
index c82c5f4db..9079c9d18 100644
--- a/extern/sector-storage/worker_local.go
+++ b/extern/sector-storage/worker_local.go
@@ -568,21 +568,32 @@ func (l *LocalWorker) GenerateWindowPoSt(ctx context.Context, ppt abi.Registered
 
 			// todo context with tighter deadline (+config)
 			vanilla, err := l.storage.GenerateSingleVanillaProof(ctx, mid, s, ppt)
+			slk.Lock()
+			defer slk.Unlock()
+
 			if err != nil || vanilla == nil {
-				slk.Lock()
 				skipped = append(skipped, abi.SectorID{
 					Miner:  mid,
 					Number: s.SectorNumber,
 				})
-				slk.Unlock()
 				log.Errorf("get sector: %d, vanilla: %s, err: %s", s.SectorNumber, vanilla, err)
 				return
 			}
+
 			vproofs[i] = vanilla
 		}(i, s)
 	}
 	wg.Wait()
 
+	var at = 0
+	for i := range vproofs {
+		if vproofs[i] != nil {
+			vproofs[at] = vproofs[i]
+			at++
+		}
+	}
+	vproofs = vproofs[:at]
+
 	res, err := sb.GenerateWindowPoStWithVanilla(ctx, ppt, mid, randomness, vproofs, partitionIdx)
 
 	return storiface.WindowPoStResult{