Are you sure it's exactly the same page or does the DB version increase a little with every page:

Vérification de la version du schéma BD... 11110 : OK.

No matter what your PHP needs to be allowed more execution time. Check out he second half of this page:

http://b2evolution.net/man/advanced-topics/troubleshooting/blank-or-partial-page

@fplanque wrote earlier:

Are you sure it's exactly the same page or does the DB version increase a little with every page:

Vérification de la version du schéma BD... 11110 : OK.

Yes I'm sure...

@fplanque wrote earlier:

No matter what your PHP needs to be allowed more execution time. Check out he second half of this page:
http://b2evolution.net/man/advanced-topics/troubleshooting/blank-or-partial-page

Ok it was solved by increasing the execution time.
But I now have a new problem in the backoffice : when displaying the "Content" tab in full post mode for the photoblog, many images are not displayed. Instead I have a black square with a red warning saying "Unable to open blablabla/fit-320x320.jpg for writing: Permission denied. I checked the permissions of caches and everything is writable. So I don't understand :(

Clearly you have a permission error. If you chmod 777 blablabla/ it will work. Then you can work on finding more secure permissions. Check the owner and group of blablabla/.

Note the most important thing here is the thing you neglect: blablabla/

@fplanque wrote earlier:

Clearly you have a permission error. If you chmod 777 blablabla/ it will work. Then you can work on finding more secure permissions. Check the owner and group of blablabla/.
Note the most important thing here is the thing you neglect: blablabla/

Ok. Thanks a lot François. In fact I indeed chmod 777 from bottom to top. But this changed nothing until I closed the browser (and the session ?). When I reopened then everything was correct.
According to you, what is the safer setting for the media and down to _evocache sub dirs? It's difficult to work more secure permissions since once the _evocache/sub-dirs exist they don't have to be recreated...
Regards.
Jacques

Error images were in your browser cache.

See this page for optimal file permissions:
http://b2evolution.net/man/advanced-topics/security/optimal-file-permissions

@fplanque wrote earlier:

Error images were in your browser cache.
See this page for optimal file permissions:
http://b2evolution.net/man/advanced-topics/security/optimal-file-permissions

Thank you again. I'll read this page carefully.
Best regards.
Jacques