my moodle page is www.esmiescuela.com/eci/virtual but I put a new icoms and I can not fix it in the resume of the site... I do not know why but I try to delet the letter in the center but none of the bootoms are active I need help
Error: Database connection failed.
Is the error I got when accessing your site. This means there is a real failure between PHP and MySQL, assuming that you are using these things. You have deleted something, but I am not sure what.
Can you recreate what you did and reverse it? That is, go back to the code and try to change it back? If you cannot, then a more radical fix can be tried.
What you may be able to do is to unzip a new copy of Moodle, then all the pages you touched, delete them, and replace them with the Moodle standard pages from the new unzip version. As long as the config.php page is intact, then it should work. This sometimes works - but sometimes it doesn't.
Outside of that, you may have to delete everything from the site and reinstall.