Yes. I had just explored all the rooms and went to save.
Do you still have this error using another save file, if you have any? I tried replicating it, but it seems to work in all the versions of mine currently - I think it might be have been an error caused by playing a previous version with bugs that hadn't been fixed yet (current one should be good to go!)
And you're playing the browser game and not any of the downloadable versions, right?
I'm due to make a new update / add new contents to this game in a day or so (likely this Friday) - I'm pretty sure it's some weird saving bug that might be using an older update for some reason. If the new game still has this bug, please try playing it on a different browser and seeing if it's got the same error? There might also be a few incompatibility things with browsers that's the issue, but I have to eliminate all the possibilites first before I can focus on which one!