After upgrading to Joomla 4: unable to edit old items

Yes for Joomla, I have updated with French version 4.3.2. For Flexicontent, I have "com_flexicontent - fr-FR version 2015-10-20-08-24-17" and "Paquet de langue français pour Flexicontent version 3.6" I have made update with latest french pack of Flexicontent on the site :  www.flexicontent.org/downloads/translations.html (no version indicated).

I have a very old installation of flexicontent and i have made many updates of Joomla and Flexicontent. May be I have olds and obsoletes parts of Flexicontent.

For me also it is a very old installation. I think that is the problem.

please
1 actived debug mode and error reporting to max to post return
2 try in englsih to be sure
3 re save all type
4 update with this github.com/FLEXIcontent/flexicontent-cck...efs/heads/master.zip

Hello,
1 actived debug mode and error reporting to max to post return OK !
2 try in englsih to be sure OK !
3 re save all type OK !
4 update with this github.com/FLEXIcontent/flexicontent-cck...efs/heads/master.zip I have one erreur on installation :


But it seem to be installed :
 

Now i can save my item but :
1) When I save it, I come back directly in the administrator panel of joomla, not in the items page of flexicontent :
 

There is an error in the installer of the french package of flexicontent, the second line must be
<filename>fr-FR.com_flexicontent.sys.ini</filename>

 

Now, when I read my saved item in the front-end, i have two new errors :

At the beginnig of the page :

Deprecated: str_replace(): Passing null to parameter #3 ($subject) of type array|string is deprecated in /home/whoswort/www/lesunimog_fr/libraries/src/Component/Router/RouterLegacy.php on line 75

At the end of the page :

Deprecated: trim(): Passing null to parameter #1 ($string) of type string is deprecated in /home/whoswort/www/lesunimog_fr/libraries/src/Document/HtmlDocument.php on line 471