diff --git a/lib/js_locale_helper.rb b/lib/js_locale_helper.rb
index 8b396707e1f..54fed140228 100644
--- a/lib/js_locale_helper.rb
+++ b/lib/js_locale_helper.rb
@@ -139,9 +139,9 @@ module JsLocaleHelper
 
     message_formats =
       I18n.fallbacks[locale]
-        .each_with_object({}) do |l, hash|
+        .each_with_object(HashWithIndifferentAccess.new) do |l, hash|
           translations = translations_for(l, no_fallback: true)
-          hash[l.to_s.dasherize] = remove_message_formats!(translations, l).merge(
+          hash[l] = remove_message_formats!(translations, l).merge(
             TranslationOverride
               .mf_locales(l)
               .pluck(:translation_key, :value)
@@ -150,7 +150,8 @@ module JsLocaleHelper
           )
         end
         .compact_blank
-    compiled = MessageFormat.compile(message_formats.keys, message_formats, strict: false)
+    js_message_formats = message_formats.transform_keys(&:dasherize)
+    compiled = MessageFormat.compile(js_message_formats.keys, js_message_formats, strict: false)
     transpiled = DiscourseJsProcessor.transpile(<<~JS, "", "discourse-mf")
       import Messages from '@messageformat/runtime/messages';
       #{compiled.sub("export default", "const msgData =")};
@@ -163,7 +164,18 @@ module JsLocaleHelper
       require("discourse-mf");
     JS
   rescue => e
-    Rails.logger.error("Failed to compile message formats for #{locale} '#{e}'")
+    js_locale = locale.to_s.dasherize
+    message_formats[locale]
+      .filter_map do |key, value|
+        next if MessageFormat.compile(js_locale, value, strict: false)
+      rescue StandardError
+        key
+      end
+      .then do |strings|
+        Rails.logger.error(
+          "Failed to compile message formats for #{locale}.\n\nBroken strings are: #{strings.join(", ")}\n\nError: #{e}",
+        )
+      end
     <<~JS
       console.error("Failed to compile message formats for #{locale}. Some translation strings will be missing.");
     JS
diff --git a/spec/lib/js_locale_helper_spec.rb b/spec/lib/js_locale_helper_spec.rb
index 55b8e908be0..5aa6a27d09c 100644
--- a/spec/lib/js_locale_helper_spec.rb
+++ b/spec/lib/js_locale_helper_spec.rb
@@ -161,25 +161,29 @@ RSpec.describe JsLocaleHelper do
     fab!(:overriden_translation_ja) do
       Fabricate(:translation_override, locale: "ja", translation_key: "js.posts_likes_MF")
     end
-    fab!(:overriden_translation_he) do
-      Fabricate(:translation_override, locale: "he", translation_key: "js.posts_likes_MF")
+    fab!(:overriden_translation_zh_tw) do
+      Fabricate(:translation_override, locale: "zh_TW", translation_key: "js.posts_likes_MF")
     end
     let(:output) { described_class.output_MF(locale).gsub(/^import.*$/, "") }
     let(:generated_locales) { v8_ctx.eval("Object.keys(I18n._mfMessages._data)") }
     let(:translated_message) do
       v8_ctx.eval("I18n._mfMessages.get('posts_likes_MF', {count: 3, ratio: 'med'})")
     end
+    let(:fake_logger) { FakeLogger.new }
 
     before do
+      Rails.logger.broadcast_to(fake_logger)
       overriden_translation_ja.update_columns(
         value: "{ count, plural, one {返信 # 件、} other {返信 # 件、} }",
       )
-      overriden_translation_he.update_columns(value: "{ count, plural, ")
+      overriden_translation_zh_tw.update_columns(value: "{ count, plural, ")
       v8_ctx.eval(output)
     end
 
+    after { Rails.logger.stop_broadcasting_to(fake_logger) }
+
     context "when locale is 'en'" do
-      let(:locale) { "en" }
+      let(:locale) { :en }
 
       it "generates messages for the 'en' locale only" do
         expect(generated_locales).to eq %w[en]
@@ -205,7 +209,7 @@ RSpec.describe JsLocaleHelper do
     end
 
     context "when locale is not 'en'" do
-      let(:locale) { "fr" }
+      let(:locale) { :fr }
 
       it "generates messages for the current locale and uses 'en' as fallback" do
         expect(generated_locales).to match(%w[fr en])
@@ -245,7 +249,7 @@ RSpec.describe JsLocaleHelper do
     end
 
     context "when locale contains invalid plural keys" do
-      let(:locale) { "ja" }
+      let(:locale) { :ja }
 
       it "does not raise an error" do
         expect(generated_locales).to match(%w[ja en])
@@ -253,11 +257,16 @@ RSpec.describe JsLocaleHelper do
     end
 
     context "when locale contains malformed messages" do
-      let(:locale) { "he" }
+      let(:locale) { :zh_TW }
 
       it "raises an error" do
         expect(output).to match(/Failed to compile message formats/)
       end
+
+      it "logs which keys are problematic" do
+        output
+        expect(fake_logger.errors).to include(/posts_likes_MF/)
+      end
     end
   end