diff --git a/FAQ.md b/FAQ.md
index b0d441d..528d4e2 100644
--- a/FAQ.md
+++ b/FAQ.md
@@ -1702,3 +1702,11 @@ If you install with RustDeskServer.setup.exe. Please backup db files and id_ed25
 The db files are under `C:\WINDOWS\ServiceProfiles\LocalService\AppData\Roaming\RustDesk\config\`, the other files are under `C:\Program Files\RustDeskServer\bin`. You can backup the two directory directly.
 
 Then please download the new RustDeskServer.setup.exe and run directly.
+
+# hbbs keeps restarting, Error: Address in use
+
+The reason is: the user also installed the rustdesk client on the server (and turn on direct acccess port 21118), there are port conflicts.
+
+https://github.com/rustdesk/rustdesk-server-pro/issues/834
+
+