diff --git a/plans/apl-on-sx.md b/plans/apl-on-sx.md
index 10fda318..e346e6ca 100644
--- a/plans/apl-on-sx.md
+++ b/plans/apl-on-sx.md
@@ -279,4 +279,6 @@ _Newest first._
 
 ## Blockers
 
-- _(none yet)_
+- 2026-05-07: **sx-tree MCP server disconnected mid-Phase-9.** `lib/apl/**.sx`
+  edits require `sx-tree` per CLAUDE.md — Edit/Read on `.sx` is hook-blocked.
+  Loop paused at Phase 9 step 2 (inline assignment); resume once MCP restored.