Good Afternoon,
This error is not one that can be put down to a single cause I'm afraid, it means that something has gone wrong and has done so in such a way that Maximizer's error handling cannot record what the problem is.
If you have recently upgraded your computers operating system then I am assuming you have re-installed Maximizer as well, I would suggest you make sure you are running all the current service packs and hotfixes for Maximizer and then make sure you run the Windows Update as well to ensure all components are updated.
If the problem persists then you should contact you Maximizer Partner for additional assistance.