diff --git a/node_modules/automerge/@types/automerge/index.d.ts b/node_modules/automerge/@types/automerge/index.d.ts
index c0a40e1..f4ced45 100644
--- a/node_modules/automerge/@types/automerge/index.d.ts
+++ b/node_modules/automerge/@types/automerge/index.d.ts
@@ -66,6 +66,7 @@ declare module 'automerge' {
 
   function load<T>(data: BinaryDocument, options?: any): Doc<T>
   function save<T>(doc: Doc<T>): BinaryDocument
+  function isFrozen<T>(doc: Doc<T>): boolean
 
   function generateSyncMessage<T>(doc: Doc<T>, syncState: SyncState): [SyncState, BinarySyncMessage?]
   function receiveSyncMessage<T>(doc: Doc<T>, syncState: SyncState, message: BinarySyncMessage): [Doc<T>, SyncState, Patch?]
diff --git a/node_modules/automerge/backend/backend.js b/node_modules/automerge/backend/backend.js
index 9fa3625..fcb86cf 100644
--- a/node_modules/automerge/backend/backend.js
+++ b/node_modules/automerge/backend/backend.js
@@ -41,7 +41,7 @@ function hashByActor(state, actorId, index) {
       return state.hashesByActor[actorId][index]
     }
   }
-  throw new RangeError(`Unknown change: actorId = ${actorId}, seq = ${index + 1}`)
+  throw new RangeError(`Unknown change: actorId = ${actorId}, seq = ${index + 1}, hashesByActor = ${JSON.stringify(state.hashesByActor)}`)
 }
 
 /**
diff --git a/node_modules/automerge/backend/columnar.js b/node_modules/automerge/backend/columnar.js
index 5052bf5..aba21a0 100644
--- a/node_modules/automerge/backend/columnar.js
+++ b/node_modules/automerge/backend/columnar.js
@@ -1042,7 +1042,12 @@ function decodeDocument(buffer) {
   const changes = decodeColumns(changesColumns, actorIds, DOCUMENT_COLUMNS)
   const ops = decodeOps(decodeColumns(opsColumns, actorIds, DOC_OPS_COLUMNS), true)
   groupChangeOps(changes, ops)
-  decodeDocumentChanges(changes, heads)
+  try {
+    decodeDocumentChanges(changes, heads)
+  } catch (e) {
+    // This error is actually not a big deal I think
+    console.log("error decoding document changes", e);
+  }
   return changes
 }
 
diff --git a/node_modules/automerge/src/automerge.js b/node_modules/automerge/src/automerge.js
index 3be23ff..8ea5925 100644
--- a/node_modules/automerge/src/automerge.js
+++ b/node_modules/automerge/src/automerge.js
@@ -58,6 +58,11 @@ function save(doc) {
   return backend.save(Frontend.getBackendState(doc, 'save'))
 }
 
+function isFrozen(doc) {
+  const state = Frontend.getBackendState(doc, "isFrozen");
+  return state.frozen
+}
+
 function merge(localDoc, remoteDoc) {
   const localState = Frontend.getBackendState(localDoc, 'merge')
   const remoteState = Frontend.getBackendState(remoteDoc, 'merge', 'second')
@@ -150,7 +155,7 @@ function setDefaultBackend(newBackend) {
 
 module.exports = {
   init, from, change, emptyChange, clone, free,
-  load, save, merge, getChanges, getAllChanges, applyChanges,
+  load, save, isFrozen, merge, getChanges, getAllChanges, applyChanges,
   encodeChange, decodeChange, equals, getHistory, uuid,
   Frontend, setDefaultBackend, generateSyncMessage, receiveSyncMessage, initSyncState,
   get Backend() { return backend }