I know where restore is from. The question is, where is your dialog handler?
Also, lskovlun is right and you should maybe include the surrounding CheckSaveGame call.
(Feel free to skip this next part if you already know this stuff.)
As you know, the saved games are stored with a file name that includes the name of the Game object. Not the class, the object instance, so KQ4 of Game saves to KQ4SG.002. Though restore is defined in class Game, it's instance KQ4 that's calling it, so it uses "KQ4" to name the files. If the objectName I see here in these two separate code blocks is from two separate objects... it'll try to restore from DEADSG.002 or whatever, if for example that dialog box with the options is handled by an object named Dead.