diff --git a/devine/commands/dl.py b/devine/commands/dl.py
index 43b4d6a..0f007fa 100644
--- a/devine/commands/dl.py
+++ b/devine/commands/dl.py
@@ -701,18 +701,22 @@ class dl:
                     ):
                         for task_id, task_tracks in multiplex_tasks:
                             progress.start_task(task_id)  # TODO: Needed?
-                            muxed_path, return_code, output = task_tracks.mux(
+                            muxed_path, return_code, errors = task_tracks.mux(
                                 str(title),
                                 progress=partial(progress.update, task_id=task_id),
                                 delete=False
                             )
                             muxed_paths.append(muxed_path)
-                            if return_code == 1:
-                                self.log.warning(output)
-                                self.log.warning("mkvmerge had at least one warning, will continue anyway...")
-                            elif return_code >= 2:
-                                self.log.warning(output)
-                                self.log.error(f"Failed to Mux video to Matroska file ({return_code})")
+                            if return_code >= 2:
+                                self.log.error(f"Failed to Mux video to Matroska file ({return_code}):")
+                            elif return_code == 1 or errors:
+                                self.log.warning("mkvmerge had at least one warning or error, continuing anyway...")
+                            for line in errors:
+                                if line.startswith("#GUI#error"):
+                                    self.log.error(line)
+                                else:
+                                    self.log.warning(line)
+                            if return_code >= 2:
                                 sys.exit(1)
                             for video_track in task_tracks.videos:
                                 video_track.delete()
diff --git a/devine/core/tracks/tracks.py b/devine/core/tracks/tracks.py
index abe9657..d70cad4 100644
--- a/devine/core/tracks/tracks.py
+++ b/devine/core/tracks/tracks.py
@@ -316,7 +316,7 @@ class Tracks:
             ][:per_language or None])
         return selected
 
-    def mux(self, title: str, delete: bool = True, progress: Optional[partial] = None) -> tuple[Path, int, str]:
+    def mux(self, title: str, delete: bool = True, progress: Optional[partial] = None) -> tuple[Path, int, list[str]]:
         """
         Multiplex all the Tracks into a Matroska Container file.
 
@@ -410,17 +410,18 @@ class Tracks:
 
         # let potential failures go to caller, caller should handle
         try:
-            output = ""
+            errors = []
             p = subprocess.Popen([
                 *cl,
                 "--output", str(output_path),
                 "--gui-mode"
             ], text=True, stdout=subprocess.PIPE)
             for line in iter(p.stdout.readline, ""):
-                output += line
+                if line.startswith("#GUI#error") or line.startswith("#GUI#warning"):
+                    errors.append(line)
                 if "progress" in line:
                     progress(total=100, completed=int(line.strip()[14:-1]))
-            return output_path, p.wait(), output
+            return output_path, p.wait(), errors
         finally:
             if chapters_path:
                 # regardless of delete param, we delete as it's a file we made during muxing