Hi Yolanda Guerrero-Rebollo,
Thanks for sharing your good mood, even in a moment of trouble.
Thanks as well for the extra details. When you write Tag, to the best of my understanding, you mean Object?
It sounds like, while the Character object was selected, you pressed the C key, which makes it editable. If you use CMD+Z directly, that is not a big problem, but later on, that is gone. I have no remedy for that later on.
Just to be clear, if we talk about the same, is that what happens?
This is typically the step when you have everything set up, and perhaps like to export the rig to a game engine for example.
Please consider for the future the following step:
• Save early, safe often
• Go to the preference…
Main Menu> Edit> Preference> Files> Autosave.
This will create copies. Sometimes that can save you hours of work.
Again, sorry for your trouble.
My best wishes.