diff --git a/frontend/common/stores/feature-list-store.ts b/frontend/common/stores/feature-list-store.ts
index b2067cf5695b..a47c9ffe27d5 100644
--- a/frontend/common/stores/feature-list-store.ts
+++ b/frontend/common/stores/feature-list-store.ts
@@ -90,8 +90,11 @@ const controller = {
       }),
       project_id: projectId,
     })
-      .then((res) =>
-        Promise.all(
+      .then((res) => {
+        if (res.error) {
+          throw res.error?.error || res.error
+        }
+        return Promise.all(
           (flag.multivariate_options || []).map((v) =>
             data
               .post(
@@ -107,8 +110,8 @@ const controller = {
           data.get(
             `${Project.api}projects/${projectId}/features/${res.data.id}/`,
           ),
-        ),
-      )
+        )
+      })
       .then(() =>
         Promise.all([
           data.get(`${Project.api}projects/${projectId}/features/`),
@@ -322,123 +325,132 @@ const controller = {
 
     store.saving()
     API.trackEvent(Constants.events.EDIT_FEATURE)
-    segmentOverridesProm.then(() => {
-      if (mode !== 'VALUE') {
-        prom = Promise.resolve()
-      } else if (environmentFlag) {
-        prom = data
-          .get(
-            `${Project.api}environments/${environmentId}/featurestates/${environmentFlag.id}/`,
-          )
-          .then((environmentFeatureStates) => {
-            const multivariate_feature_state_values =
-              environmentFeatureStates.multivariate_feature_state_values &&
-              environmentFeatureStates.multivariate_feature_state_values.map(
-                (v) => {
-                  const matching =
-                    environmentFlag.multivariate_feature_state_values.find(
-                      (m) => m.id === v.multivariate_feature_option,
-                    ) || {}
-                  return {
-                    ...v,
-                    percentage_allocation:
-                      matching.default_percentage_allocation,
-                  }
-                },
-              )
-            environmentFlag.multivariate_feature_state_values =
-              multivariate_feature_state_values
-            return data.put(
+    segmentOverridesProm
+      .then(() => {
+        if (mode !== 'VALUE') {
+          prom = Promise.resolve()
+        } else if (environmentFlag) {
+          prom = data
+            .get(
               `${Project.api}environments/${environmentId}/featurestates/${environmentFlag.id}/`,
-              Object.assign({}, environmentFlag, {
-                enabled: flag.default_enabled,
-                feature_state_value: Utils.getTypedValue(
-                  flag.initial_value,
-                  undefined,
-                  true,
-                ),
-              }),
             )
-          })
-      } else {
-        prom = data.post(
-          `${Project.api}environments/${environmentId}/featurestates/`,
-          Object.assign({}, flag, {
-            enabled: false,
-            environment: environmentId,
-            feature: projectFlag,
-          }),
-        )
-      }
-
-      const segmentOverridesRequest =
-        mode === 'SEGMENT' && segmentOverrides
-          ? (segmentOverrides.length
-              ? updateSegmentPriorities(
-                  getStore(),
-                  segmentOverrides.map((override, index) => ({
-                    id: override.id,
-                    priority: index,
-                  })),
+            .then((environmentFeatureStates) => {
+              const multivariate_feature_state_values =
+                environmentFeatureStates.multivariate_feature_state_values &&
+                environmentFeatureStates.multivariate_feature_state_values.map(
+                  (v) => {
+                    const matching =
+                      environmentFlag.multivariate_feature_state_values.find(
+                        (m) => m.id === v.multivariate_feature_option,
+                      ) || {}
+                    return {
+                      ...v,
+                      percentage_allocation:
+                        matching.default_percentage_allocation,
+                    }
+                  },
                 )
-              : Promise.resolve([])
-            ).then(() =>
-              Promise.all(
-                segmentOverrides.map((override) =>
-                  data.put(
-                    `${Project.api}features/featurestates/${override.feature_segment_value.id}/`,
-                    {
-                      ...override.feature_segment_value,
-                      enabled: override.enabled,
-                      feature_state_value: Utils.valueToFeatureState(
-                        override.value,
-                      ),
-                      multivariate_feature_state_values:
-                        override.multivariate_options &&
-                        override.multivariate_options.map((o) => {
-                          if (o.multivariate_feature_option) return o
-                          return {
-                            multivariate_feature_option:
-                              environmentFlag.multivariate_feature_state_values[
-                                o.multivariate_feature_option_index
-                              ].multivariate_feature_option,
-                            percentage_allocation: o.percentage_allocation,
-                          }
-                        }),
-                    },
+              environmentFlag.multivariate_feature_state_values =
+                multivariate_feature_state_values
+              return data.put(
+                `${Project.api}environments/${environmentId}/featurestates/${environmentFlag.id}/`,
+                Object.assign({}, environmentFlag, {
+                  enabled: flag.default_enabled,
+                  feature_state_value: Utils.getTypedValue(
+                    flag.initial_value,
+                    undefined,
+                    true,
                   ),
-                ),
-              ),
-            )
-          : Promise.resolve()
-
-      Promise.all([prom, segmentOverridesRequest]).then(([res, segmentRes]) => {
-        if (store.model) {
-          store.model.keyedEnvironmentFeatures[projectFlag.id] = res
-          if (segmentRes) {
-            const feature = _.find(
-              store.model.features,
-              (f) => f.id === projectFlag.id,
-            )
-            if (feature) {
-              feature.feature_segments = _.map(
-                segmentRes.feature_segments,
-                (segment) => ({
-                  ...segment,
-                  segment: segment.segment.id,
                 }),
               )
-            }
-          }
+            })
+        } else {
+          prom = data.post(
+            `${Project.api}environments/${environmentId}/featurestates/`,
+            Object.assign({}, flag, {
+              enabled: false,
+              environment: environmentId,
+              feature: projectFlag,
+            }),
+          )
         }
 
-        if (store.model) {
-          store.model.lastSaved = new Date().valueOf()
-        }
-        onComplete && onComplete()
-        store.saved({})
+        const segmentOverridesRequest =
+          mode === 'SEGMENT' && segmentOverrides
+            ? (segmentOverrides.length
+                ? updateSegmentPriorities(
+                    getStore(),
+                    segmentOverrides.map((override, index) => ({
+                      id: override.id,
+                      priority: index,
+                    })),
+                  )
+                : Promise.resolve([])
+              ).then(() =>
+                Promise.all(
+                  segmentOverrides.map((override) =>
+                    data.put(
+                      `${Project.api}features/featurestates/${override.feature_segment_value.id}/`,
+                      {
+                        ...override.feature_segment_value,
+                        enabled: override.enabled,
+                        feature_state_value: Utils.valueToFeatureState(
+                          override.value,
+                        ),
+                        multivariate_feature_state_values:
+                          override.multivariate_options &&
+                          override.multivariate_options.map((o) => {
+                            if (o.multivariate_feature_option) return o
+                            return {
+                              multivariate_feature_option:
+                                environmentFlag
+                                  .multivariate_feature_state_values[
+                                  o.multivariate_feature_option_index
+                                ].multivariate_feature_option,
+                              percentage_allocation: o.percentage_allocation,
+                            }
+                          }),
+                      },
+                    ),
+                  ),
+                ),
+              )
+            : Promise.resolve()
+
+        Promise.all([prom, segmentOverridesRequest])
+          .then(([res, segmentRes]) => {
+            if (store.model) {
+              store.model.keyedEnvironmentFeatures[projectFlag.id] = res
+              if (segmentRes) {
+                const feature = _.find(
+                  store.model.features,
+                  (f) => f.id === projectFlag.id,
+                )
+                if (feature) {
+                  feature.feature_segments = _.map(
+                    segmentRes.feature_segments,
+                    (segment) => ({
+                      ...segment,
+                      segment: segment.segment.id,
+                    }),
+                  )
+                }
+              }
+            }
+
+            if (store.model) {
+              store.model.lastSaved = new Date().valueOf()
+            }
+            onComplete && onComplete()
+            store.saved({})
+          })
+          .catch((e) => {
+            API.ajaxHandler(store, e)
+          })
+      })
+      .catch((e) => {
+        API.ajaxHandler(store, e)
       })
-    })
   },
   editFeatureStateChangeRequest: async (
     projectId: string,
@@ -770,13 +782,17 @@ const controller = {
       )
     }
 
-    prom.then((res) => {
-      if (store.model) {
-        store.model.lastSaved = new Date().valueOf()
-      }
-      onComplete && onComplete()
-      store.saved({})
-    })
+    prom
+      .then((res) => {
+        if (store.model) {
+          store.model.lastSaved = new Date().valueOf()
+        }
+        onComplete && onComplete()
+        store.saved({})
+      })
+      .catch((e) => {
+        API.ajaxHandler(store, e)
+      })
   },
   getFeatureUsage(projectId, environmentId, flag, period) {
     data
diff --git a/frontend/web/components/ErrorMessage.js b/frontend/web/components/ErrorMessage.js
index cbf1832f6c7e..b50f644e6093 100644
--- a/frontend/web/components/ErrorMessage.js
+++ b/frontend/web/components/ErrorMessage.js
@@ -28,7 +28,9 @@ export default class ErrorMessage extends PureComponent {
         <span className='icon-alert'>
           <Icon name='close-circle' />
         </span>
-        {typeof error === 'object' ? (
+        {error instanceof Error ? (
+          error.message
+        ) : typeof error === 'object' ? (
           <div
             dangerouslySetInnerHTML={{
               __html: Object.keys(error)
diff --git a/frontend/web/project/api.js b/frontend/web/project/api.js
index 1f33a17a6bf4..8ac745d78ec9 100644
--- a/frontend/web/project/api.js
+++ b/frontend/web/project/api.js
@@ -16,6 +16,11 @@ global.API = {
     }
 
     // Catch coding errors that end up here
+    if (typeof res === 'string') {
+      store.error = new Error(res)
+      store.goneABitWest()
+      return
+    }
     if (res instanceof Error) {
       console.error(res)
       store.error = res