This guide deals with the specific issue of not being able to switch to Mahjong mode from the hidden object scenes. This bug prevents obtainment of the Mahjong-related achievements.

This bug is manifested when you move the mouse cursor over the Mahjong icon but the cursor shows a "Back" icon instead of highlighting the Mahjong icon.

This bug is caused by completing the first hidden object scene in Mahjong mode. If that is done, then from that point on all future hidden object scenes will "lock out" the Mahjong mode.

It is possible that there are other causes, for example interaction with the Tutorial which I have not thouroughly tested.

To avoid the bug, simply ensure that you complete the first hidden object scene in hidden object mode.

If you have already progressed into the game and are suffering the effects of the bug, there does not appear to be a way to recover Mahjong mode in the current playthrough. But if it is your first time playing you may wish to complete the playthrough anyway, as to get 100% you will need to play a second time regardless.

Ideally, the most efficient way to get through the game with 100% achievements is to:
1. Play Mahjong for the first HO scene (causing the bug to occur), and play in HO mode for the remainder of the game.
2. On second playthrough, play in HO mode for the first scene and then play in Mahjong mode for the remainder of the game.