I think the devil may be in the details on this one. I’ve been tracking a few very similar issues. All of which have completely different root causes. The symptom of failed/out-of-sync preview is general enough to encompass a lot of different “illnesses”.
It should go without saying, but if you’re experiencing a strange issue then Realmac and YourHead would like to take a look at your project and see what you’re seeing and hopefully get the problem fixed. So send your projects our way.
If you’re inclined to try to understand a bit more yourself, here’s some stuff I’ve noticed. This is really just for folks that would like to tinker and understand the issues a bit more.
RW v8.0.3 seems to have corrected a number of internal issues that causes exporting to fail/crash/give-up.
Result: check your misbehaving pages in the recent build.
Be aware that there are some new project-wide settings and app-wide preferences in RW8. If you’ve changed some of these it can affect how your project is being updated.
Slow exports behave differently. RW8 does more asynchronously, and very slow things can result in repeat exports or even looping exports.
Result: If you see repeating exports for a single preview, or looping exports send your project to RMS or YourHead to have them take a look.
And this last one is for the truly adventurous nerd that likes to dive deep.
Compare and Contrast
One great way to isolate issues is to run RW7 and RW8 side by side on the same project. Since RW8 made a copy of your project file, you can open both. It’s fun to run them side by side and compare apples-to-apples.
Result: If you notice any big discrepancies between the two, send your project file or a step by step procedure about how to see the discrepency