diff --git a/app/javascript/bootcamp/return.js b/app/javascript/bootcamp/return.js
index bf0aa93429..2f9d5ae5b9 100644
--- a/app/javascript/bootcamp/return.js
+++ b/app/javascript/bootcamp/return.js
@@ -19,6 +19,12 @@ async function initialize() {
   const response = await fetch(
     `/courses/stripe/session-status?session_id=${sessionId}&enrollment_uuid=${enrollmentUuid}`
   )
+
+  if (!response.ok) {
+    window.location.replace(failurePath)
+    return
+  }
+
   const session = await response.json()
 
   if (session.status == 'open') {
diff --git a/app/javascript/components/ErrorBoundary.tsx b/app/javascript/components/ErrorBoundary.tsx
index d4196665c9..ba836e0cab 100644
--- a/app/javascript/components/ErrorBoundary.tsx
+++ b/app/javascript/components/ErrorBoundary.tsx
@@ -94,19 +94,25 @@ export const useErrorHandler = (
 
       handler(new HandledError(defaultError.message))
     } else if (error instanceof Response) {
-      error
-        .clone()
-        .json()
-        .then((res: { error: APIError }) => {
-          handler(new HandledError(res.error.message))
-        })
-        .catch((e) => {
-          if (process.env.NODE_ENV == 'production') {
-            Sentry.captureException(e)
-          }
-
-          handler(new HandledError(defaultError.message))
-        })
+      const contentType = error.headers.get('Content-Type')
+      const isJson =
+        contentType &&
+        (contentType.includes('application/json') ||
+          contentType.includes('+json'))
+
+      if (isJson) {
+        error
+          .clone()
+          .json()
+          .then((res: { error: APIError }) => {
+            handler(new HandledError(res.error.message))
+          })
+          .catch(() => {
+            handler(new HandledError(defaultError.message))
+          })
+      } else {
+        handler(new HandledError(defaultError.message))
+      }
     }
   }, [defaultError, error, handler])
 }
diff --git a/app/javascript/components/profile/avatar-selector/cropping-modal/CropFinishedStep.tsx b/app/javascript/components/profile/avatar-selector/cropping-modal/CropFinishedStep.tsx
index 2412c1cdab..1563d170c9 100644
--- a/app/javascript/components/profile/avatar-selector/cropping-modal/CropFinishedStep.tsx
+++ b/app/javascript/components/profile/avatar-selector/cropping-modal/CropFinishedStep.tsx
@@ -49,6 +49,7 @@ export const CropFinishedStep = ({
       /* TODO: (optional) Use our standard sendRequest library */
       return fetch(links.update, { body: formData, method: 'PATCH' })
         .then((response) => {
+          if (!response.ok) throw response
           return response.json().then((json) => camelizeKeys(json))
         })
         .then((json) => {
diff --git a/app/javascript/hooks/use-theme-observer/patch-theme.ts b/app/javascript/hooks/use-theme-observer/patch-theme.ts
index 1a63c00349..1a67792ba4 100644
--- a/app/javascript/hooks/use-theme-observer/patch-theme.ts
+++ b/app/javascript/hooks/use-theme-observer/patch-theme.ts
@@ -11,7 +11,10 @@ function patchTheme(theme: string, updateEndpoint?: string) {
       user_preferences: { theme },
     }),
   })
-    .then((res) => res.json())
+    .then((res) => {
+      if (!res.ok) throw new Error('Failed to update theme')
+      return res.json()
+    })
     .catch((e) =>
       // eslint-disable-next-line no-console
       console.error('Failed to update to accessibility-dark theme: ', e)