diff --git a/Error-messages.md b/Error-messages.md
index 9aeb162..7ff5a65 100644
--- a/Error-messages.md
+++ b/Error-messages.md
@@ -8,6 +8,7 @@
 
 ### Source directory is empty
 * Selected directory don't contain any image files.
+  * You cannot use the 'directory' feature with e.g. CBR files. Add them manually by multi-selection via "Add File"
 
 ### Failed to extract images from PDF file
 * PDF file has too complex structure.