diff --git a/FreeSql/Internal/CommonProvider/UpdateProvider.cs b/FreeSql/Internal/CommonProvider/UpdateProvider.cs
index 431664d2..780761b4 100644
--- a/FreeSql/Internal/CommonProvider/UpdateProvider.cs
+++ b/FreeSql/Internal/CommonProvider/UpdateProvider.cs
@@ -1144,7 +1144,7 @@ namespace FreeSql.Internal.CommonProvider
                     }
             }
 
-            if (_versionColumn != null)
+            if (_versionColumn != null && _versionColumn.Attribute.CanUpdate)
             {
                 var vcname = _commonUtils.QuoteSqlName(_versionColumn.Attribute.Name);
                 if (_versionColumn.Attribute.MapType == typeof(byte[]))
diff --git a/FreeSql/Internal/UtilsExpressionTree.cs b/FreeSql/Internal/UtilsExpressionTree.cs
index dc178ef9..34c1e7bc 100644
--- a/FreeSql/Internal/UtilsExpressionTree.cs
+++ b/FreeSql/Internal/UtilsExpressionTree.cs
@@ -327,7 +327,7 @@ namespace FreeSql.Internal
                     }
                 }
                 if (colattr.MapType == typeof(string) && colattr.IsVersion == true) colattr.StringLength = 40;
-                if (colattr.MapType == typeof(byte[]) && colattr.IsVersion == true) colattr.StringLength = 16;
+                if (colattr.MapType == typeof(byte[]) && colattr.IsVersion == true) colattr.StringLength = 16; // 8=sqlserver timestamp, 16=GuidToBytes
                 if (colattr.MapType == typeof(byte[]) && colattr.StringLength != 0)
                 {
                     int strlen = colattr.StringLength;