diff --git a/src/settings.cpp b/src/settings.cpp
--- a/src/settings.cpp
+++ b/src/settings.cpp
@@ -1631,7 +1631,7 @@ static GRFConfig *GRFLoadConfig(IniFile 
 				SetDParam(1, STR_CONFIG_ERROR_INVALID_GRF_UNKNOWN);
 			}
 
-			SetDParamStr(0, StrEmpty(filename) ? item->name.c_str() : filename);
+			SetDParamStr(0, StrEmpty(filename) ? item->name : filename);
 			ShowErrorMessage(STR_CONFIG_ERROR, STR_CONFIG_ERROR_INVALID_GRF, WL_CRITICAL);
 			delete c;
 			continue;