If you wish to see page history and you have newly built Forge macros on some page version, then it just shows red error as the content.
How to reproduce it:
- Add some forge macros to page.
- Create some changes to generate versions of the page.
- Open Page History and select some historic version to view.
- Error!
It is most likely related also to the new Editor thing. Thus is there somehow maybe possible to force this small view to use this new editor somehow. The same error appears if you create new confluence page via api and do not specify that it needs new Editor. So then also if the page content has not converted you can see just errors instead of macro results.