to 1.: I sent the access data via email...
But currently the error cannot be found. I fixed the error by deleting the "html" folder.
The error occurred on the entire site after the update to Bianca Template J4... No special menu item

Thank you for the update.

Unfortunately, the override (html) folder can pose an issue for us when upgrading a template. The Joomla 3 version of the template contains overrides that should be removed for the Joomla 4 version to function correctly. We can delete this folder during the update process however this may not always be desired if a user has created their own custom overrides and wish to keep them when updating. We have been looking for a way around this however it is difficult to find a one fix for all solution.

In the meantime all we can suggest is to delete all non custom overrides prior to updating.

Ciaran

Thank you for reporting!

1. Would you happen to know which menu item type did you have this issue (eg.. Category blog, single article etc.)?

2. This issue should be resolved by simply opening your module settings and saving them. The latest version of the icons module has some extra settings that may be missing from your database.

Ciaran

Good Morning.
to 1. The first page was a "J51_Bianca - One Page Website" I can't say which menu type it is
I have now updated a second, different website to J4. also with BIANCA. Also there comes the 500 error message.
(by deleting the html folder and reinstalling the biance template, the 500 error is gone )
Here it was linked to the template styles: "J51_Bianca - Homepage" and J51_Bianca - Default". The main menu is standard on both sides. I haven't changed anything in the menus on the website.

To 2. OK. Saving EVERYONE! _icon modules fixes the warning !

3. NEW!: On the second website with Bianca, the J51_news MODUL and the j51_numbers MODUL are defective. (J_news version 3.0.12 J_ version 1.0.2 ) if I re-upload the exact same module version from the templates folder the error is also fixed!

Hello

1. May I suggest sending temporary administration access to your Joomla installation to info@joomla51.com and we will examine this issue further. If you could also indicate a menu item where the issue occurs that would be great. For our reference please paste a link to this post in your email.

2. Nice. Thank you for the update!

3. THis issue was mentioned to us previously however at the time I was unable to replicate the problem. I will take another luck. Thank you for reporting.

Ciaran