diff --git a/test/foundationdb/docker-compose.arm64.yml b/test/foundationdb/docker-compose.arm64.yml
index 683c967d1..9eda8db42 100644
--- a/test/foundationdb/docker-compose.arm64.yml
+++ b/test/foundationdb/docker-compose.arm64.yml
@@ -154,7 +154,7 @@ services:
       WEED_LEVELDB2_ENABLED: "false"
       WEED_FOUNDATIONDB_ENABLED: "true"
       WEED_FOUNDATIONDB_CLUSTER_FILE: "/var/fdb/config/fdb.cluster"
-      WEED_FOUNDATIONDB_API_VERSION: "720"
+      WEED_FOUNDATIONDB_API_VERSION: "740"
       WEED_FOUNDATIONDB_TIMEOUT: "5s"
       WEED_FOUNDATIONDB_MAX_RETRY_DELAY: "1s"
       WEED_MASTER_VOLUME_GROWTH_COPY_1: 1
diff --git a/weed/filer/foundationdb/CONFIGURATION.md b/weed/filer/foundationdb/CONFIGURATION.md
index f4a73afe0..80f5bd357 100644
--- a/weed/filer/foundationdb/CONFIGURATION.md
+++ b/weed/filer/foundationdb/CONFIGURATION.md
@@ -23,7 +23,7 @@ All configuration options can be set via environment variables with the `WEED_FO
 ```bash
 export WEED_FOUNDATIONDB_ENABLED=true
 export WEED_FOUNDATIONDB_CLUSTER_FILE=/etc/foundationdb/fdb.cluster
-export WEED_FOUNDATIONDB_API_VERSION=720
+export WEED_FOUNDATIONDB_API_VERSION=740
 export WEED_FOUNDATIONDB_TIMEOUT=5s
 export WEED_FOUNDATIONDB_MAX_RETRY_DELAY=1s
 export WEED_FOUNDATIONDB_DIRECTORY_PREFIX=seaweedfs
@@ -274,7 +274,7 @@ location = "/backup"
 # Docker environment
 WEED_FOUNDATIONDB_ENABLED=true
 WEED_FOUNDATIONDB_CLUSTER_FILE=/var/fdb/config/fdb.cluster
-WEED_FOUNDATIONDB_API_VERSION=720
+WEED_FOUNDATIONDB_API_VERSION=740
 ```
 
 ### Kubernetes ConfigMap
diff --git a/weed/filer/foundationdb/INSTALL.md b/weed/filer/foundationdb/INSTALL.md
index 101097a8e..7b3b128fa 100644
--- a/weed/filer/foundationdb/INSTALL.md
+++ b/weed/filer/foundationdb/INSTALL.md
@@ -135,7 +135,7 @@ Alternative configuration via environment variables:
 ```bash
 export WEED_FOUNDATIONDB_ENABLED=true
 export WEED_FOUNDATIONDB_CLUSTER_FILE=/etc/foundationdb/fdb.cluster
-export WEED_FOUNDATIONDB_API_VERSION=720
+export WEED_FOUNDATIONDB_API_VERSION=740
 export WEED_FOUNDATIONDB_TIMEOUT=5s
 export WEED_FOUNDATIONDB_MAX_RETRY_DELAY=1s
 export WEED_FOUNDATIONDB_DIRECTORY_PREFIX=seaweedfs
diff --git a/weed/filer/foundationdb/README.md b/weed/filer/foundationdb/README.md
index cde3e00b5..68ba6416a 100644
--- a/weed/filer/foundationdb/README.md
+++ b/weed/filer/foundationdb/README.md
@@ -71,7 +71,7 @@ Configure via environment variables:
 ```bash
 export WEED_FOUNDATIONDB_ENABLED=true
 export WEED_FOUNDATIONDB_CLUSTER_FILE=/etc/foundationdb/fdb.cluster
-export WEED_FOUNDATIONDB_API_VERSION=720
+export WEED_FOUNDATIONDB_API_VERSION=740
 export WEED_FOUNDATIONDB_TIMEOUT=5s
 export WEED_FOUNDATIONDB_MAX_RETRY_DELAY=1s
 export WEED_FOUNDATIONDB_DIRECTORY_PREFIX=seaweedfs
diff --git a/weed/filer/foundationdb/foundationdb_store.go b/weed/filer/foundationdb/foundationdb_store.go
index d9c2925ee..23f53c3e0 100644
--- a/weed/filer/foundationdb/foundationdb_store.go
+++ b/weed/filer/foundationdb/foundationdb_store.go
@@ -381,6 +381,7 @@ func (store *FoundationDBStore) ListDirectoryPrefixedEntries(ctx context.Context
 	for _, kv := range kvs {
 		fileName := store.extractFileName(kv.Key)
 		if fileName == "" {
+			glog.V(0).Infof("list %s: failed to extract fileName from key %v", dirPath, kv.Key)
 			continue
 		}
 
@@ -447,6 +448,9 @@ func (store *FoundationDBStore) KvGet(ctx context.Context, key []byte) ([]byte,
 	}
 
 	if err != nil || len(data) == 0 {
+		if err != nil {
+			glog.V(2).Infof("KvGet error for key %v: %v", key, err)
+		}
 		return nil, filer.ErrKvNotFound
 	}
 
@@ -489,12 +493,18 @@ func (store *FoundationDBStore) genDirectoryKeyPrefix(dirPath, prefix string) fd
 
 func (store *FoundationDBStore) extractFileName(key fdb.Key) string {
 	t, err := store.seaweedfsDir.Unpack(key)
-	if err != nil || len(t) < 2 {
+	if err != nil {
+		glog.V(4).Infof("extractFileName: unpack error for key %v: %v", key, err)
+		return ""
+	}
+	if len(t) < 2 {
+		glog.V(4).Infof("extractFileName: tuple too short (len=%d) for key %v", len(t), key)
 		return ""
 	}
 
 	if fileName, ok := t[1].(string); ok {
 		return fileName
 	}
+	glog.V(4).Infof("extractFileName: second element not a string (type=%T) for key %v", t[1], key)
 	return ""
 }
diff --git a/weed/filer/foundationdb/foundationdb_store_test.go b/weed/filer/foundationdb/foundationdb_store_test.go
index 69bc0c156..f76fa57df 100644
--- a/weed/filer/foundationdb/foundationdb_store_test.go
+++ b/weed/filer/foundationdb/foundationdb_store_test.go
@@ -20,7 +20,7 @@ func TestFoundationDBStore_Initialize(t *testing.T) {
 	// Test with default configuration
 	config := util.GetViper()
 	config.Set("foundationdb.cluster_file", getTestClusterFile())
-	config.Set("foundationdb.api_version", 630)
+	config.Set("foundationdb.api_version", 740)
 
 	store := &FoundationDBStore{}
 	err := store.Initialize(config, "foundationdb.")
@@ -42,7 +42,7 @@ func TestFoundationDBStore_Initialize(t *testing.T) {
 func TestFoundationDBStore_InitializeWithCustomConfig(t *testing.T) {
 	config := util.GetViper()
 	config.Set("foundationdb.cluster_file", getTestClusterFile())
-	config.Set("foundationdb.api_version", 630)
+	config.Set("foundationdb.api_version", 740)
 	config.Set("foundationdb.timeout", "10s")
 	config.Set("foundationdb.max_retry_delay", "2s")
 	config.Set("foundationdb.directory_prefix", "custom_prefix")
@@ -118,7 +118,7 @@ func TestFoundationDBStore_InitializeInvalidConfig(t *testing.T) {
 
 func TestFoundationDBStore_KeyGeneration(t *testing.T) {
 	store := &FoundationDBStore{}
-	err := store.initialize(getTestClusterFile(), 720)
+	err := store.initialize(getTestClusterFile(), 740)
 	if err != nil {
 		t.Skip("FoundationDB not available for testing, skipping")
 	}
@@ -158,7 +158,7 @@ func TestFoundationDBStore_KeyGeneration(t *testing.T) {
 
 func TestFoundationDBStore_DirectoryKeyPrefix(t *testing.T) {
 	store := &FoundationDBStore{}
-	err := store.initialize(getTestClusterFile(), 720)
+	err := store.initialize(getTestClusterFile(), 740)
 	if err != nil {
 		t.Skip("FoundationDB not available for testing, skipping")
 	}
@@ -187,7 +187,7 @@ func TestFoundationDBStore_DirectoryKeyPrefix(t *testing.T) {
 
 func TestFoundationDBStore_ErrorHandling(t *testing.T) {
 	store := &FoundationDBStore{}
-	err := store.initialize(getTestClusterFile(), 720)
+	err := store.initialize(getTestClusterFile(), 740)
 	if err != nil {
 		t.Skip("FoundationDB not available for testing, skipping")
 	}
@@ -227,7 +227,7 @@ func TestFoundationDBStore_ErrorHandling(t *testing.T) {
 
 func TestFoundationDBStore_TransactionState(t *testing.T) {
 	store := &FoundationDBStore{}
-	err := store.initialize(getTestClusterFile(), 720)
+	err := store.initialize(getTestClusterFile(), 740)
 	if err != nil {
 		t.Skip("FoundationDB not available for testing, skipping")
 	}