diff --git a/instances.yml b/instances.yml
index a3f62f469..42b5aa11f 100644
--- a/instances.yml
+++ b/instances.yml
@@ -637,3 +637,116 @@ lpnmr-hard-instances:
 - ipc: ipc-2002
   domain: driverlog-strips-automatic
   instance: 18
+
+lpnmr-first-plan-not-serializable:
+- ipc: ipc-1998
+  domain: mystery-round-1-strips
+  instance: 2
+- ipc: ipc-1998
+  domain: mystery-round-1-strips
+  instance: 6
+- ipc: ipc-1998
+  domain: mystery-round-1-strips
+  instance: 9
+- ipc: ipc-1998
+  domain: mystery-round-1-strips
+  instance: 10
+- ipc: ipc-1998
+  domain: mystery-round-1-strips
+  instance: 13
+- ipc: ipc-1998
+  domain: mystery-round-1-strips
+  instance: 15
+- ipc: ipc-1998
+  domain: mystery-round-1-strips
+  instance: 19
+- ipc: ipc-1998
+  domain: mystery-round-1-strips
+  instance: 20
+- ipc: ipc-1998
+  domain: mystery-round-1-strips
+  instance: 26
+- ipc: ipc-1998
+  domain: mystery-round-1-strips
+  instance: 27
+- ipc: ipc-1998
+  domain: mystery-round-1-strips
+  instance: 29
+- ipc: ipc-1998
+  domain: mystery-round-1-strips
+  instance: 30
+- ipc: ipc-2000
+  domain: freecell-strips-typed
+  instance: 1
+- ipc: ipc-2000
+  domain: freecell-strips-typed
+  instance: 2
+- ipc: ipc-2000
+  domain: freecell-strips-typed
+  instance: 3
+- ipc: ipc-2000
+  domain: freecell-strips-typed
+  instance: 4
+- ipc: ipc-2000
+  domain: freecell-strips-typed
+  instance: 5
+- ipc: ipc-2000
+  domain: freecell-strips-typed
+  instance: 6
+- ipc: ipc-2000
+  domain: freecell-strips-typed
+  instance: 7
+- ipc: ipc-2000
+  domain: freecell-strips-typed
+  instance: 8
+- ipc: ipc-2000
+  domain: freecell-strips-typed
+  instance: 9
+- ipc: ipc-2000
+  domain: freecell-strips-typed
+  instance: 10
+- ipc: ipc-2000
+  domain: freecell-strips-typed
+  instance: 11
+- ipc: ipc-2000
+  domain: freecell-strips-typed
+  instance: 12
+- ipc: ipc-2000
+  domain: freecell-strips-typed
+  instance: 13
+- ipc: ipc-2000
+  domain: freecell-strips-typed
+  instance: 14
+- ipc: ipc-2000
+  domain: freecell-strips-typed
+  instance: 15
+- ipc: ipc-2000
+  domain: freecell-strips-typed
+  instance: 19
+- ipc: ipc-2002
+  domain: driverlog-strips-automatic
+  instance: 7
+- ipc: ipc-2002
+  domain: driverlog-strips-automatic
+  instance: 9
+- ipc: ipc-2002
+  domain: driverlog-strips-automatic
+  instance: 11
+- ipc: ipc-2002
+  domain: driverlog-strips-automatic
+  instance: 12
+- ipc: ipc-2002
+  domain: driverlog-strips-automatic
+  instance: 13
+- ipc: ipc-2002
+  domain: driverlog-strips-automatic
+  instance: 14
+- ipc: ipc-2002
+  domain: driverlog-strips-automatic
+  instance: 15
+- ipc: ipc-2002
+  domain: driverlog-strips-automatic
+  instance: 17
+- ipc: ipc-2002
+  domain: driverlog-strips-automatic
+  instance: 18