Add strings.

en.json

@@ -229,6 +229,11 @@
         "too_short": "Too short",
         "too_long": "Too long",
         "invalid_email": "Invalid email address",
-        "unavailable": "Unavailable."
+        "unavailable": "Unavailable.",
+        "file_too_large": "File is too large.",
+        "failed_to_receive": "Server failed to receive your file.",
+        "missing_data": "Request is missing data.",
+        "probe_error": "Failed to get file metadata.",
+        "io_error": "Server encountered an I/O error."
     }
 }