Please check attachment. I have a fresh
Magento 2.3.0 installation. Unable to upload a logo.
The error says "A technical problem with the server created an error. Try again to continue what you were doing. If the problem persists, try again later."
JQMIGRATE: deferred.pipe() is deprecated at /adminhtml/Magento/backend/en_US/jquery/jquery-migrate.jsjquery-migrate.js:45