diff --git a/app/imports/api/creature/Creatures.js b/app/imports/api/creature/Creatures.js
index 654270c5..6aba8479 100644
--- a/app/imports/api/creature/Creatures.js
+++ b/app/imports/api/creature/Creatures.js
@@ -96,6 +96,11 @@ let CreatureSchema = new SimpleSchema({
 		type: Number,
 		defaultValue: 0,
 	},
+  // Version of computation engine that was last used to compute this creature
+  computeVersion: {
+		type: String,
+    optional: true,
+	},
 	type: {
 		type: String,
 		defaultValue: 'pc',
diff --git a/app/imports/api/creature/computation/computeEndStepProperty.js b/app/imports/api/creature/computation/computeEndStepProperty.js
index 3ae9924a..091cc2bb 100644
--- a/app/imports/api/creature/computation/computeEndStepProperty.js
+++ b/app/imports/api/creature/computation/computeEndStepProperty.js
@@ -34,6 +34,7 @@ function computeAction(prop, memo){
   if (prop.usesUsed >= prop.usesResult){
     prop.insufficientResources = true;
   }
+  if (!prop.resources) return;
   // Attributes consumed
   prop.resources.attributesConsumed.forEach((attConsumed, i) => {
     if (attConsumed.variableName){
diff --git a/app/imports/api/creature/computation/recomputeCreature.js b/app/imports/api/creature/computation/recomputeCreature.js
index 6e81836b..a2f3d298 100644
--- a/app/imports/api/creature/computation/recomputeCreature.js
+++ b/app/imports/api/creature/computation/recomputeCreature.js
@@ -102,12 +102,12 @@ export function recomputeCreatureByDoc(creature){
     'ancestors.id': creatureId,
     inactive: {$ne: true},
     type: {$in: calculationPropertyTypes},
+    // TODO filter out expensive fields, particularly icon field
   }).fetch();
   /*getActiveProperties({
     ancestorId: creatureId,
     filter: {type: {$in: calculationPropertyTypes}},
     includeUntoggled: true,
-    // TODO filter out expensive fields, particularly icon field
   });*/
   let computationMemo = new ComputationMemo(props, creature);
   computeMemo(computationMemo);
diff --git a/app/imports/api/creature/computation/writeCreatureVariables.js b/app/imports/api/creature/computation/writeCreatureVariables.js
index 7ab7aa95..4622a5cb 100644
--- a/app/imports/api/creature/computation/writeCreatureVariables.js
+++ b/app/imports/api/creature/computation/writeCreatureVariables.js
@@ -1,5 +1,6 @@
 import { pick, forOwn } from 'lodash';
 import Creatures from '/imports/api/creature/Creatures.js';
+import VERSION from '/imports/constants/VERSION.js';
 
 export default function writeCreatureVariables(memo, creatureId) {
   const fields = [
@@ -31,5 +32,8 @@ export default function writeCreatureVariables(memo, creatureId) {
     let condensedStat = pick(stat, fields);
     memo.creatureVariables[variableName] = condensedStat;
   });
-  Creatures.update(creatureId, {$set: {variables: memo.creatureVariables}});
+  Creatures.update(creatureId, {$set: {
+    variables: memo.creatureVariables,
+    computeVersion: VERSION,
+  }});
 }
diff --git a/app/imports/constants/VERSION.js b/app/imports/constants/VERSION.js
new file mode 100644
index 00000000..5adefb3b
--- /dev/null
+++ b/app/imports/constants/VERSION.js
@@ -0,0 +1,6 @@
+
+const VERSION = Meteor.isClient ? 'CLIENT' : process.env.SOURCE_VERSION || require('child_process')
+  .execSync('git rev-parse --short HEAD')
+  .toString().trim();
+
+export default VERSION;
diff --git a/app/imports/server/publications/singleCharacter.js b/app/imports/server/publications/singleCharacter.js
index de2de40e..2b5bb64c 100644
--- a/app/imports/server/publications/singleCharacter.js
+++ b/app/imports/server/publications/singleCharacter.js
@@ -3,6 +3,8 @@ import Creatures from '/imports/api/creature/Creatures.js';
 import CreatureProperties from '/imports/api/creature/CreatureProperties.js';
 import CreatureLogs from '/imports/api/creature/log/CreatureLogs.js';
 import { assertViewPermission } from '/imports/api/creature/creaturePermissions.js';
+import { recomputeCreatureById } from '/imports/api/creature/computation/recomputeCreature.js';
+import VERSION from '/imports/constants/VERSION.js';
 
 let schema = new SimpleSchema({
   creatureId: {
@@ -28,8 +30,13 @@ Meteor.publish('singleCharacter', function(creatureId){
       ],
     });
     try {
-      assertViewPermission(creatureCursor.fetch()[0], userId);
+      let creature = creatureCursor.fetch()[0];
+      assertViewPermission(creature, userId);
+      if (creature.computeVersion !== VERSION){
+        recomputeCreatureById(creatureId)
+      }
     } catch (e){
+      console.error(e);
       return [];
     }
     return [
diff --git a/app/imports/ui/properties/components/actions/ActionCard.vue b/app/imports/ui/properties/components/actions/ActionCard.vue
index 4ae1cef9..dcd0566c 100644
--- a/app/imports/ui/properties/components/actions/ActionCard.vue
+++ b/app/imports/ui/properties/components/actions/ActionCard.vue
@@ -49,7 +49,7 @@
     </div>
     <div class="px-3 pb-3">
       <template
-        v-if="model.resources.attributesConsumed.length ||
+        v-if="model.resources && model.resources.attributesConsumed.length ||
           model.resources.itemsConsumed.length"
       >
         <attribute-consumed-view