diff --git a/main.py b/main.py
--- a/main.py
+++ b/main.py
@@ -2,8 +2,10 @@ import argparse
 import asyncio
 import json
 import queue
+import shutil
 import threading
 from collections.abc import Callable
+from pathlib import Path
 from typing import Any
 
 import env
@@ -62,6 +64,23 @@ args = parser.parse_args()
 
     if args.flush_caches:
         flush_caches()
+        return
+
+    def _test_binary(binary: str) -> bool:
+        if "/" in binary or "\\" in binary:
+            return Path(binary).exists()
+        return shutil.which(binary) is not None
+
+    if not _test_binary(env.FFMPEG_PATH):
+        LOGGER.error(
+            "ffmpeg is required to crosspost media, but was not found!", env.FFMPEG_PATH
+        )
+        return
+    if not _test_binary(env.FFPROBE_PATH):
+        LOGGER.error(
+            "ffprobe is required to crosspost media, but was not found!",
+            env.FFPROBE_PATH,
+        )
         return
 
     if not env.DATA_DIR.exists():