Cannot Create Report or Dashboard Folder in Lightning Experience

The issue of not being able to create a Report or Dashboard folder is resolved by ensuring that the Unique Folder Name field only contains alphanumeric characters and underscores.

Symptom:
The following error message appears when attempting to create a Report or Dashboard folder in Lightning Experience: "The folder named (folder name) could not be created." In Salesforce Classic, the error displayed is "Invalid Data," but Lightning Experience does not show the specific reason for the error.

Resolution Steps:
・In the folder creation screen, check the Unique Folder Name field.
・Use only alphanumeric characters and underscores (_) in this field. double-byte characters, spaces, hyphens (-), and other symbols are not permitted.