Confirmed see JC Tracker: http://joomlacode.org/gf/project/joomla/tracker/?action=TrackerItemEdit&tracker_item_id=34047&start=0

The var self::$homes contain only the value how much home menus we have see here:

https://github.com/joomla/joomla-cms/blob/staging/administrator/components/com_languages/helpers/multilangstatus.php#L21-33

This check was introduced by @infograf768 with: 1672fcd

But i have no clue how this should work.

Doesn't look like correct code.
MultilangstatusHelper::getHomes() only returns the count of home menu items.
MultilangstatusHelper::getHomepages() would return the languages, but also not the ids. However it would be easy to add the ids there and use this method.

I can't reproduce the error here.
can you explain your settings: multilanguage on? PHP, etc.

I couldn't reproduce it myself, but code is clearly wrong

The code is only reached if some conditions are met and I'm not sure what they all do. You need to get into this else: https://github.com/joomla/joomla-cms/blob/staging/plugins/system/languagefilter/languagefilter.php#L533

What I gathered is that it only happens when the user logs in and the plugin is set to automatically change the language. I think it's in the case that the language actually has changed due to the user logging in but there isn't a matching associated menu item. Then it should redirect to the language homepage and the plugin tries to find the matching Itemid to create a proper redirect. That fails because self::$homes only contains a number and isn't an array of objects as assumed by the code.

I was able to reproduce the error on my web site www.webtrees.net.

1) I selected the French language
2) Selected the Forum (Kunena) icon.
3) Entered a un/pw and then CR.
This produced the error in the apache log.

PHP version 5.4.31
In the Language Manager, I have two languages; English (UK) and French (fr-FR).

PHP version 5.4.31
No language is selected in the Extension/Install Language (FrenchCA is the only one but not selected)
We use the French Language/Package, version 3.3.3.1 from www.joomla.fr

Actually, I may have stated that wrong. In the Language Manager, I have two languages; English (UK) and French (fr-FR).

Did you intend to close this one? I'm reopening because I think it's a valid issue.

I updated the title to make it clearer
You may blame the J!Tracker Application for transmitting this comment.

Tested when associations is off and I confirm the Warning.

This comment was created with the J!Tracker Application at issues.joomla.org/joomla-cms/4079.

Please test

#4944

This comment was created with the J!Tracker Application at issues.joomla.org/joomla-cms/4079.

Set to "closed" on behalf of @brianteeman by The JTracker Application at issues.joomla.org/joomla-cms/4079