diff --git a/README.md b/README.md
index 6eecb66..e7ec677 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,8 @@
 # Self-hosted LiveSync
 
+IMPORTANT NOTICE: In 0.10.0, database upgraded incompatiblly. And automatic migration fails in some cases. 
+If you are troubled, please downgrade orelse "drop old encrypted database" and "drop and send"(or receive) again.
+
 Sorry for late! [Japanese docs](./README_ja.md) is also coming up.
 
 **Renamed from: obsidian-livesync**