diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9ac0c08..311daac 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,14 +7,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
-### Revert
-
-- Use old app-store-seller major for client
-
 ### Fixed
 
-- Use new app-store-seller major for client
-- Shows error message when an API call request didn't complete, such as in a Timeout
+- Handle non-JSON error messages in submit 400 responses instead of crashing the CLI
 
 ## [1.1.0] - 2021-11-22
 
diff --git a/src/lib/constants/Messages.ts b/src/lib/constants/Messages.ts
index 42c2fe5..01cd729 100644
--- a/src/lib/constants/Messages.ts
+++ b/src/lib/constants/Messages.ts
@@ -11,6 +11,10 @@ export const Messages = {
 
   APP_NOT_INSTALLED:
     "The app you're trying to submit must be installed on this workspace.",
+
+  VALIDATION_FAILED_UNKNOWN_REASON:
+    'Your submission could not be validated. Make sure your app is both published and deployed before running `vtex submit`, then try again. If the problem persists, contact VTEX support.',
+
   ENTER_GITHUB_USERNAME: 'Enter your Github username',
   ENTER_STATUS_CHECK_URL:
     'Enter a URL from where we can test your app working. It can be in your workspace',
diff --git a/src/modules/submit.ts b/src/modules/submit.ts
index 99ed28e..7ae45b4 100644
--- a/src/modules/submit.ts
+++ b/src/modules/submit.ts
@@ -14,7 +14,20 @@ const handleSubmitAppError = (e: any) => {
 
   switch (status) {
     case 400: {
-      logger.error(Messages.OBJECT_FORMAT, JSON.parse(response?.data?.message))
+      try {
+        logger.error(
+          Messages.OBJECT_FORMAT,
+          JSON.parse(response?.data?.message)
+        )
+      } catch {
+        // response.data.message isn't valid JSON (e.g. an upstream service propagated
+        // a raw error string instead of a structured validation payload). Surface a
+        // clear, actionable message instead of letting the SyntaxError bubble up raw.
+        logger.error(
+          response?.data?.message ?? Messages.VALIDATION_FAILED_UNKNOWN_REASON
+        )
+      }
+
       break
     }