Improve message when asking for a game_path with no filepicker available

data/language/en-GB.txt

@@ -3652,6 +3652,7 @@ STR_6395    :Maintenance
 STR_6396    :Disable screensaver and monitor power saving
 STR_6397    :{SMALLFONT}{BLACK}If checked, screensaver and other monitor power saving features will be inhibited while OpenRCT2 is running.
 STR_6398    :File contains unsupported ride types. Please update to a newer version of OpenRCT2.
+STR_6399    :OpenRCT2 needs files from the original RollerCoaster Tycoon 2 in order to work. Please set the "game_path" variable in config.ini to the directory where you installed RollerCoaster Tycoon 2, then restart OpenRCT2.
 
 #############
 # Scenarios #

src/openrct2/config/Config.cpp

@@ -794,12 +794,18 @@ bool config_find_or_browse_install_directory()
             return false;
         }
 
+        auto uiContext = GetContext()->GetUiContext();
+        if (!uiContext->HasFilePicker())
+        {
+            uiContext->ShowMessageBox(format_string(STR_NEEDS_RCT2_FILES_MANUAL, nullptr));
+            return false;
+        }
+
         try
         {
             const char* g1DatPath = PATH_SEPARATOR "Data" PATH_SEPARATOR "g1.dat";
             while (true)
             {
-                auto uiContext = GetContext()->GetUiContext();
                 uiContext->ShowMessageBox(format_string(STR_NEEDS_RCT2_FILES, nullptr));
 
                 std::string installPath = uiContext->ShowDirectoryDialog(format_string(STR_PICK_RCT2_DIR, nullptr));

src/openrct2/localisation/StringIds.h

@@ -3903,6 +3903,9 @@ enum
     STR_DISABLE_SCREENSAVER_TIP = 6397,
 
     STR_FILE_CONTAINS_UNSUPPORTED_RIDE_TYPES = 6398,
+
+    STR_NEEDS_RCT2_FILES_MANUAL = 6399,
+
     // Have to include resource strings (from scenarios and objects) for the time being now that language is partially working
     /* MAX_STR_COUNT = 32768 */ // MAX_STR_COUNT - upper limit for number of strings, not the current count strings
 };