Hey @coliveira2001 welcome to the Nextcloud community 
You posted a request in the support category. Unfortunately you ignored the template and a lot of information to help you is missing. Please edit your original post and add all required details like Nextcloud version, webserver type and version, os version, related log file content. Use the support template.
Without additional information the community members cannot help you.
meanwhile, try removing the deleted users user directory from the datadirectory of the web server followed by occ files:scan --all and the try adding that user again.