The provided output name either already exists or contains invalid characters. Output names cannot include the following special characters: <, >, #, %, :, ;, ", ?, &, +, =, |, /, \, *, or @. Output names beginning or ending with spaces are also invalid.
Solution
Remove any unsupported spaces and characters from the output name. If there are no spaces or special characters, it means the name is currently in use by a different hosted layer in the ArcGIS organization. Provide a new name that is unique in your ArcGIS organization.