I already found SOLUTION.
It had nothing to do with an ERROR, to activate the Debug mode, I contacted my Hosting and when I told them why I wanted to activate it, they made a review and they responded to the following:
“I have disabled a security rule that apparently affected you”
And when I did the test to save the configuration, I no longer had a problem and the message remained active:
“Configuration was saved.
Rewrite rules were saved to the following files … “
Thanks for the help!