diff --git a/x-pack/plugins/fleet/server/services/managed_package_policies.ts b/x-pack/plugins/fleet/server/services/managed_package_policies.ts
index e78bc096b8711..c702cfe96d986 100644
--- a/x-pack/plugins/fleet/server/services/managed_package_policies.ts
+++ b/x-pack/plugins/fleet/server/services/managed_package_policies.ts
@@ -74,7 +74,7 @@ export const upgradeManagedPackagePolicies = async (
       if (dryRunResults.hasErrors) {
         const errors = dryRunResults.diff
           ? dryRunResults.diff?.[1].errors
-          : dryRunResults.body?.message;
+          : [dryRunResults.body?.message];
 
         appContextService
           .getLogger()
diff --git a/x-pack/plugins/fleet/server/services/setup.ts b/x-pack/plugins/fleet/server/services/setup.ts
index 1c84073552e57..d39a5f4473199 100644
--- a/x-pack/plugins/fleet/server/services/setup.ts
+++ b/x-pack/plugins/fleet/server/services/setup.ts
@@ -220,8 +220,15 @@ export function formatNonFatalErrors(
         name: e.error.name,
         message: e.error.message,
       };
-    } else {
+    } else if ('errors' in e) {
       return e.errors.map((upgradePackagePolicyError: any) => {
+        if (typeof upgradePackagePolicyError === 'string') {
+          return {
+            name: 'SetupNonFatalError',
+            message: upgradePackagePolicyError,
+          };
+        }
+
         return {
           name: upgradePackagePolicyError.key,
           message: upgradePackagePolicyError.message,