Thanks for your respons.
1. with 1700+ items per page your server memory is not exhausted, but the PHP memory limitation per script execution is reached (or do you get a timeout? page loads for more than 60/120 seconds ?)
If you enable PHP error reporting inside some PHP file, prior to limit being reached, then will see a relevant message
Well, I obtain immediatly a white page, without message, even in debug mode.
About Joomla modules not showing, please check your configuration that controls when these modules are shown
I done, it's ok. In fact, they are on category page, so it's good, but they don't be showed on item page.
And you have not answered me if these modules are Universal Content Modules.
I said it's Joomla standards modules, like latests news, search module and so on. I don't use Universal Content Module, I never succeded to have what I want with it.
And why do you think that this is related to FLEXIcontent ?
Because all was good before I made the update of Flexicontent.
Anyway it is IMPOSSIBLE to say anything without access to the site
This site contains personnal and professionnal data. I try to tell the site's owners if they are ok, but I don't think so...
Thanks for all.