Another glaring example of Adobe coldly abandoning its Fireworks users. There's an updater for CS6 for the new Mavericks OS, but no updated for CS5.
Adobe keeps making me dislike it more. Wish Macromedia had never sold Fireworks. At least they had some enthusiasm about the app.
And I'm not about to be sucked into the pay-in-perpetuity scheme called Cloud, in which they make whatever tweaks to the app that they feel like making whether I want 'em or not. At least in sticking to CS5 I have an app that I know, without unrequested, un-cancellable "improvement" changes.
Guess I'll just have to live with the new, erroneous "Could not save this file" prompts in CS5 and renew my Adobe disgust each time the prompt rears its meaningless little window.
Then LEAVE Adobe software, and use alternatives. Complaining about the current situation will not sway Adobe management team - the decision was made to stop Fireworks development. Fact of life, unfortunately.
Change is always hard; look for alternatives, and vote with your wallet.
Btw, as far as I recall, Macromedia itself was considering to discontinue Fireworks right before it was bought out by Adobe.