PB 3.0 not displaying existing pages correctly

I've had 2 sites today with this issue after updating to the latest PB version.

I'll open an existing article (built in a PB version prior to 3.0) and, though I can see the text, images, or whatever, as soon as I open the block containing the content, there's nothing there. (see images).

I turned on Max error reporting and debug, but nothing shows.

I have version 2.18.10 in my downloads folder. If I reinstall that, editing is normal. It doesn't seem to be an issue with 3.0.0 created content, just those articles created in past versions.

UPDATE: Just added a new article in a site I'm building. Originally started with PB 2.18.10, but since upgraded to 3.0.0. Added content, saved as normal... but everything has gone. Reinstalled 2.18.10, and everything is back to working.

Hi
Please contact me by email to give me an admin access to one of these websites, where you have the 3.0.0 not working so that I can check
CEd

Bonjour CeD,
je vais pas ré-ouvrir un nouveau topic en Français mais j'ai exactement le même problème, quand j'ai fait la mise à jour sur mon site test, du coup je n'ai pas fait la mise à jour sur mes sites en production.
Bonne journée
Olivier

Salut
peux-tu me contacter par email pour me donner un accès admin ?
CEd

@trogaldyte : please clear your browser cache and tell me if it works

@CED

I updated a site that I previously had to downgrade. Again, on the initial install of 3.0.0 it failed. However, I did a Clear Cache as requested, and that seems to have fixed the issue - articles are editable again.

I do not have any cache active on this site.