I’ve got the same issue (kind of) right now. I have two common screens that will not load due to the failed validation error message. In the Customization Workbench, there are no errors and no warnings.
I’ve tried everything I can think of, but no joy. I got a third to work by moving fields around on the screen. But now the personalizations are giving me a lot of issues on that one.
Before Customization Workbench validation:
:TOP
After Customization Workbench Validation:
After trying to load it:
Then in customization workbench:
GOTO TOP
EDIT
I just realized that on my “Pass” it was listing it as w3.2.700.0 … very weird. I ended up exporting the customization, importing it with a different name, changed the menu item, relaunched and everything works just fine.