Error on the Create Translation screen for custom menu links

Can you confirm you have followed the installation instructions for the module, particularly the requirement to choose, install and set up an AI Provider to handle the connection to your chosen AI service? And if so, have you visited the AI Settings page to select a default provider and model for translations?

I am trying to gradually phase in the AI module, so my AI provider only has the chat set up in Gemini.

One question.
Why do I need to set up all providers that I do not plan to use?

Sorry I'm losing you: are you saying "Yes I have followed the instructions to set up an AI Provider (can you link to it for us as well?) and have set the AI's modules default settings to say which provider to use for translations"?

Sorry, it is very possible that I do not understand the whole picture of the AI module and its configuration.
After uninstalling the AI Translate module, the error disappeared.

Even if the AI translation module is poorly configured, the inability to translate menu items manually as usual is still a problem.
I am attaching a screenshot.
I cropped the screen capture, but there is nothing at the bottom of the error message.

Can you confirm which of these provider modules you have installed on the site? https://project.pages.drupalcode.org/ai/providers/matris/

I can't confirm your issue without being able to replicate your set-up.

As your screenshot shows, there is a message asking you to do something before you can translate the menu item, including a link to where you need to do it: I also need you to confirm you have done that, because otherwise it is likely the issue is you have misconfigured the module not that the module has a bug.

Just to add, the second error in the description is a duplicate of https://www.drupal.org/project/ai/issues/3513409 🐛 Warning: Undefined array key "#entity" in Drupal\ai_translate\Form\AiTranslateForm Active and should be resolved by the patch there.

Still require the information in my previous comment to investigate this further.

Settings at the time of first submission

admin/config/ai/settings

Embeddings
Default provider: No default

Speech to Speech
Default provider: No default

Chat
Default provider: Gemini
Default Model: Gemini 1.5 Flash

Image Classification
Default provider: No default

Image and Audio to Video
Default provider: No default

Speech To Text
Default provider: No default

Text To Speech
Default provider: No default

Image to Video
Default provider: No default

Text To Image
Default provider: No default

Translate Text
Default provider: No default

Moderation
Default provider: No default

Chat with Image Vision
Default provider: No default

Chat with Complex JSON
Default provider: No default

admin/config/ai/ai-translate

AI model used for translating to Japanese: —Default from AI module (chat)—

AI model used for translating to English: —Default from AI module (chat)—

AI model used for translating to German: —Default from AI module (chat)—

AI model used for translating to French: —Default from AI module (chat)—

----------
Second validation settings (current)

admin/config/ai/settings

Chat
Default provider: Gemini
Default Model: Gemini 1.5 Flash

Translate Text
Default provider: Chat proxy to LLM
Default provider: Gemini 1.5 Flash

admin/config/ai/ai-translate

AI model used for translating to Japanese: Gemini - Gemini 1.5 Flash

AI model used for translating to English: Gemini - Gemini 1.5 Flash

AI model used for translating to German: Gemini - Gemini 1.5 Flash

AI model used for translating to French: Gemini - Gemini 1.5 Flash

Error message
Warning: Undefined array key "#entity" in Drupal\ai_translate\Form\AiTranslateForm->buildForm() (line 85 of modules/contrib/ai/modules/ai_translate/src/Form/AiTranslateForm.php).

Incidentally, uninstalling the AI Translater module (ai_tmgmt) did not remove the error.

Translate Text
Default provider: No default

That looks to be the issue: is it possible to set your chosen provider and model in that section?

The "Warning: Undefined array key "#entity"" error is fixed by the patch in the linked ticket, not by uninstalling any modules.