I was playing Bruce Lee 2 from a USB stick (I've just finished it: awesome game! Big thank you to the people who wrote it and ported it, it was a real trip down memory lane).
Basically I did not care about an ultimate challenge, I was happy just playing the game to see how it would end; so I decided to save the state every time I got past some difficult point. So I saved like a gazillion times, each time overwriting one of the four "slots". This worked until today. I saved a game, and instead of the snapshot I got the generic "empty memory slot" picture, the one with the BASIC screen. Luckily (since I had overwritten a previous save point which I wanted to retain) rebooting the Mini revealed that the original save point had not been overwritten, it was still there. And now I could once again save new points to that location and to other locations, so I thought oh well, a glitch.
Except it happened again, and again. I had to reboot every time.
It could be down to space on the nand,have you saved any other games on TheC64 Mini,the more saves you make the more space it uses,I think the nand only has 256 mb of space and thats not a lot,and more games you add to the Carousel that uses more space too.
Have you added games to the Carousel and have you saved(snapshot) a lot of games from USB,if the nand runs out of space or its too low it will not save the shapshot of the game..?
Aside from Bruce Lee 2, I only have saved games for another game (Star Paws). I did not add games to the Carousel. Besides, rebooting without deleting any saved game resulted in temporarily restoring the ability to save. Finally, since I was continuously overwriting the same 4 slots, I don't think I could have run out of space anyway unless the overwritten slots are not actually deleted and stack up. It still looks like a problem with the storage or a firmware bug.
If you're running the game from a USB stick, then it should be saving your game states on the USB stick as well. I don't have my stick handy, but there should be a directory that says something like 'thec64 saves' or something along those lines. If it's on the Mini itself, there's only a few megabytes of space left, so each of the 64 games with 4 slots shouldn't run out of that. It could be a problem with reading/writing to your USB media too, occasionally I've noticed mine simply just dropping the USB drive out of nowhere and only a reboot of the mini fixes it permanently. Not sure what's causing it.
maxframes , you should check does it happen with other games. If not, it could be related to this version of game. Sometimes, in VICE (v2.4) at PC, with some games, it is happened to - you're saving a game snapshot, but when you try to load it, it seems that saved .vsf is broken. Could it be that "Carousel" just erase that faulty file? In normal circumstances, at Mini, it should happen only if nand memory becomes faulty - e.g. rewritten thousands of time. There is another possibility: Many users noticed disappearing of picture for a second, occasionally. It is related to power, probably. If you had such experience, it could be possible that peak of the voltage that is needed, in some millisecond is not strong enough to save game properly. What I want to say is: You have try changing USB memory storage (stick), and then try to change power adapter. And repeat testing with some other game. At least, you will know that it is not related to power, stick or game.
Please, share us results.
Btw, I was aware that Bruce Lee 2 is a great game, but still didn't play it! Thanks for that. Could you confirm that it could be played by two players simultaneously (as I heard, iirc)?
I haven't tried with two players, also because I don't have a second joystick. But a funny thing with the game is that the villain characters (including a more defined black Ninja, a cameo from Green Yamo and Chuck Norris and Kareem Abdul Jabbar lookalikes) will start fighting each other when Bruce is not around. =)
I never renamed the file, there is no extra space and this issue came and went; I think it's a problem with the USB drive rather than something else. My guess is this happens when the USB drive becomes inaccessible.