diff --git a/kernel/api/attr.go b/kernel/api/attr.go
index af996f660..0c1d2dbcc 100644
--- a/kernel/api/attr.go
+++ b/kernel/api/attr.go
@@ -58,7 +58,11 @@ func setBlockAttrs(c *gin.Context) {
 	attrs := arg["attrs"].(map[string]interface{})
 	nameValues := map[string]string{}
 	for name, value := range attrs {
-		nameValues[name] = value.(string)
+		if nil == value { // API `setBlockAttrs` 中如果存在属性值设置为 `null` 时移除该属性 https://github.com/siyuan-note/siyuan/issues/5577
+			nameValues[name] = ""
+		} else {
+			nameValues[name] = value.(string)
+		}
 	}
 	err := model.SetBlockAttrs(id, nameValues)
 	if nil != err {
diff --git a/kernel/model/assets_watcher.go b/kernel/model/assets_watcher.go
index ef2ebad03..b12e08da8 100644
--- a/kernel/model/assets_watcher.go
+++ b/kernel/model/assets_watcher.go
@@ -53,7 +53,7 @@ func watchAssets() {
 	}
 
 	go func() {
-		logging.Recover()
+		defer logging.Recover()
 
 		var (
 			timer     *time.Timer