diff --git a/Source/increadimail_convert.h b/Source/increadimail_convert.h
index 6e89423..3787421 100644
--- a/Source/increadimail_convert.h
+++ b/Source/increadimail_convert.h
@@ -24,6 +24,7 @@
 #define MAX_CHAR 256
 
 typedef enum INCREDIMAIL_VERSIONS {
+   INCREDIMAIL_VERSION_UNKNOWN,
    INCREDIMAIL_XE,
    INCREDIMAIL_2,
 };
diff --git a/Source/incredimail_convert.c b/Source/incredimail_convert.c
index b267deb..05e1e8a 100644
--- a/Source/incredimail_convert.c
+++ b/Source/incredimail_convert.c
@@ -348,7 +348,7 @@ int total_count = 1;
 
 enum INCREDIMAIL_VERSIONS FindIncredimailVersion( char *directory_search ) {
 char temp_path[MAX_CHAR];
-enum INCREDIMAIL_VERSIONS ret;
+enum INCREDIMAIL_VERSIONS ret = INCREDIMAIL_VERSION_UNKNOWN;
 WIN32_FIND_DATA FindFileData;
 HANDLE hFind;
 
diff --git a/Source/winmain.c b/Source/winmain.c
index 4dc413b..a639243 100644
--- a/Source/winmain.c
+++ b/Source/winmain.c
@@ -586,6 +586,13 @@ enum INCREDIMAIL_VERSION incredimail_version;
          read_length = ReadOneLine( inputfile, im_database_filename, MAX_CHAR );
          // cleaning up the line feeds from FindDatabaseFiles function
          i = (int) strlen( im_database_filename );
+		 if (i < 2) {
+			 char msg[MAX_CHAR];
+			 snprintf(msg, MAX_CHAR, "Ignoring invalid filename %s", im_database_filename);
+			 MessageBox(global_hwnd, msg, "Error!", MB_OK);
+			 continue;
+		 }
+
          im_database_filename[i-2] = 0;
 
          if( read_length != 0 ) {
@@ -601,6 +608,11 @@ enum INCREDIMAIL_VERSION incredimail_version;
             pdest = strrchr( im_database_filename, '\\' );
             strncpy_s( temp_path, sizeof(temp_path), im_database_filename, strlen( im_database_filename ) - strlen( pdest ) );
             incredimail_version = FindIncredimailVersion( temp_path );
+			if (incredimail_version == INCREDIMAIL_VERSION_UNKNOWN) {
+				char msg[CHAR_MAX];
+				sprintf_s(msg, CHAR_MAX, "Directory %s doesn't match a known Incredimail version", temp_path);
+				continue;
+			}
 
             if( incredimail_version == INCREDIMAIL_XE ) {
                // get the header filename