diff --git a/src/runtime/actors.rs b/src/runtime/actors.rs
index bf56da5fc034ebaac67ffcfc63822ba84468b629..d47ad39644c7b60806e31e35bdf2f692227d0704 100644
--- a/src/runtime/actors.rs
+++ b/src/runtime/actors.rs
@@ -323,10 +323,10 @@ impl PolyP {
                             if payload_branch.blocking_on == Some(ekey) {
                                 // run the fork
                                 payload_branch.blocking_on = None;
-                                Some((old_predicate, payload_branch))
+                                Some((payload_predicate.clone(), payload_branch))
                             } else {
                                 // don't bother running. its awaiting something else
-                                incomplete2.insert(old_predicate, payload_branch);
+                                incomplete2.insert(payload_predicate.clone(), payload_branch);
                                 None
                             }
                         }
@@ -379,6 +379,7 @@ impl PolyN {
             let mut report_if_solution =
                 |branch: &BranchN, pred: &Predicate, logger: &mut String| {
                     if branch.to_get.is_empty() {
+                        log!(logger, "Native reporting solution with inbox {:#?}", &branch.gotten);
                         solution_storage.submit_and_digest_subtree_solution(
                             logger,
                             SubtreeId::PolyN,
@@ -396,14 +397,14 @@ impl PolyN {
             );
             match case {
                 Csr::Nonexistant => { /* skip branch */ }
-                Csr::FormerNotLatter | Csr::Equivalent => {
+                Csr::LatterNotFormer | Csr::Equivalent => {
                     // Feed the message to this branch in-place. no need to modify pred.
                     if branch.to_get.remove(&ekey) {
                         branch.gotten.insert(ekey, payload.clone());
                         report_if_solution(&branch, &old_predicate, logger);
                     }
                 }
-                Csr::LatterNotFormer => {
+                Csr::FormerNotLatter => {
                     // create a new branch with the payload_predicate.
                     let mut forked = branch.clone();
                     if forked.to_get.remove(&ekey) {
@@ -422,15 +423,10 @@ impl PolyN {
                     }
                 }
             }
-            // unlike PolyP machines, Native branches do not become inconsistent
+            // unlike PolyP machines, Native branches do NOT become inconsistent
             branches2.insert(old_predicate, branch);
         }
-        log!(
-            logger,
-            "Native now has {} branches with predicates: {:?}",
-            branches2.len(),
-            branches2.keys().collect::<Vec<_>>()
-        );
+        log!(logger, "Native now has branches {:#?}", &branches2);
         std::mem::swap(&mut branches2, &mut self.branches);
     }
 
diff --git a/src/runtime/communication.rs b/src/runtime/communication.rs
index de60b08c48c85b876fd30ee2694586df218b16f1..e7595a26225f9768e0f34f37f5567810c43cd62a 100644
--- a/src/runtime/communication.rs
+++ b/src/runtime/communication.rs
@@ -7,8 +7,15 @@ impl Controller {
         let ret = match &decision {
             Decision::Success(predicate) => {
                 // overwrite MonoN/P
-                self.inner.mono_n =
-                    self.ephemeral.poly_n.take().unwrap().choose_mono(predicate).unwrap();
+                self.inner.mono_n = {
+                    let poly_n = self.ephemeral.poly_n.take().unwrap();
+                    poly_n.choose_mono(predicate).unwrap_or_else(|| {
+                        panic!(
+                            "Ending round with decision pred {:#?} but poly_n has branches {:#?}. My log is... {}",
+                            &predicate, &poly_n.branches, &self.inner.logger
+                        );
+                    })
+                };
                 self.inner.mono_ps.clear();
                 self.inner.mono_ps.extend(
                     self.ephemeral
@@ -419,6 +426,7 @@ impl Controller {
                     return self.end_round_with_decision(decision);
                 }
                 CommMsgContents::SendPayload { payload_predicate, payload } => {
+                    // check that we expect to be able to receive payloads from this sender
                     assert_eq!(
                         Getter,
                         self.inner.endpoint_exts.get(received.recipient).unwrap().info.polarity
@@ -434,6 +442,17 @@ impl Controller {
                         &payload_predicate,
                         &payload
                     );
+                    let channel_id = self
+                        .inner
+                        .endpoint_exts
+                        .get(received.recipient)
+                        .expect("UEHFU")
+                        .info
+                        .channel_id;
+                    if payload_predicate.query(channel_id) != Some(true) {
+                        // sender didn't preserve the invariant
+                        return Err(SyncErr::PayloadPremiseExcludesTheChannel(channel_id));
+                    }
                     match subtree_id {
                         None => {
                             // this happens when a message is sent to a component that has exited.
@@ -455,17 +474,6 @@ impl Controller {
                         }
                         Some(PolyId::P { index }) => {
                             // Message for protocol actor
-                            let channel_id = self
-                                .inner
-                                .endpoint_exts
-                                .get(received.recipient)
-                                .expect("UEHFU")
-                                .info
-                                .channel_id;
-                            if payload_predicate.query(channel_id) != Some(true) {
-                                // sender didn't preserve the invariant
-                                return Err(SyncErr::PayloadPremiseExcludesTheChannel(channel_id));
-                            }
                             let poly_p = &mut self.ephemeral.poly_ps[*index];
 
                             let m_ctx = PolyPContext {