troubles with 1.21

@philippeg - I don't have an answer for you and you are the first to report any problems. I've passed a link to this post along to other core developers and hopefully someone will have an idea very soon for you. 

I'll do some testing to see if I can replicate this problem. 

Hi, sorry for your troubles.

I'm trying to recreate your issue on my test site. I haven't been able to so far. This is what I did:

Created a fresh Backdrop site with version 1.20.3. Added some pages and added them to the Primary Navigation. It's a mono-lingual site with no contributed modules enabled.

I then upgraded the site 1.21.0 and ran upgrade.php. Cleared all caches. The same number of menu items in the primary navigation. No duplicates.

So there might be some other contributed module that's helping to cause your issue. Or perhaps the site was an upgrade from Drupal 7 and there's some odd configuration still around?

You mention "each update.php". Does that mean this has been happening with previous code upgrades as well?

I wish you luck in tracking this down.

Hello @philippeg 👋

Sorry this is giving you a hard time. Can you please post a list of the contributed modules that you have enabled on the site?

Another option you can consider is to join us during our weekly Office Hours, where we can troubleshoot this together.

Do the sites have all the same modules enabled? If not which are common between the two sites?

Can you navigate to admin/structure/menu/ , open the Primary Navigation menu (click Manage links) and check if you see duplications in that listing of links? (I assume that the menu shown on your screenshot is the Primary Navigation).

What theme are you using? Are you using the Layout API to display the menu on your home page, or is this menu "hard printed" by your theme? Check the home page layout by visiting admin/structure/layouts and clicking on Manage blocks for the Home page. Check if a Primary Navigation block is actually included there in the Header or another region.

Like others in this thread, I think that this is the result of some unexpected interaction with a contrib module. I'm wondering especially about the Menu Node API module, which creates new tables in the database. Install your site in a local environment to avoid messing it up further, and try to disable that module (you'll need to disable MEnu Node Views first). Then clear caches and check if that does anything. 

I think it was mentioned before, but if you are able to come to office hours or weekly meetings - we might be able to be more help. 

https://backdropcms.org/news/events

This seems like a hard one to diagnose in the forum. So far, we haven't gotten another other reports of a similar problem.

:-(

@philippeg - We created a ticket in the core issue queue and it seems that we might have some ideas about what is causing this. 

You might want to check the progress of this ticket and provide any additional information you think might help. 

https://github.com/backdrop/backdrop-issues/issues/5460

@philippeg this abécédaire page of which the menu items get duplicated - what sort of page is that? Is it a view or some module provided page?

If it's a view: does it have a menu item set by the views UI?

If it's a module - a public contrib one, or a custom one? Does it implement hook_menu?

Many thanks for the infos.

have this problem on site where this abécédaire doesn't exist;

...

i have done test with others menus on the same site and i have duplicates links too

I didn't mean to suggest, that this exact page causes the problem - it's not your page alone, we discovered some hidden duplication.

What we still struggle with, is to reproduce the duplication of visible menu items. Being able to do that, might help to understand what exactly is going on.

So any info you provide can be helpful and is appreciated. We're planning to provide a bugfix update soon.