I reply here to both Lucas and Hamza. I went back on my steps, rebuilding a couple of submenu I have deleted before, thus I was able to re-delete all my test stuff. Now the main menu is clean and back to the original state. Thank you for your support.

i there. Not sure if it helps you or not. But if I were you, I would note this:.

[object with reference: wizard.ir.model.menu.create - wizard.ir.model.menu.create]

Where it says wizard.ir.model.menu.create, I would go to the developer mode, and search in models/views or other places for this and try to fix it from the python coding there. You can try that. There is definitely something there, which has other records linked to them. Play with it a few more times, you'll get through it. I always did when playing with these validation errors.

Good Luck.