You may find the need to restrict or permit certain file types from being uploaded to or used on pages. This can be proactive (i.e. as part of the page planning process) or reactive based on a request or receiving an error like:
Audience: Self-service, Admin/SuperUser
1. With your SuperUser/Admin account, login to your instance and use the Persona Bar to select Settings > Security.
2. On the security page that pops up, select More > More Security Settings and you will see Allowable File Extensions at the bottom.
3. Edit the list accordingly using a comma in between each entry and click Save.
4. Attempt to upload a file type that you modified on a page to verify if the changes have worked. If you edited to restrict a file type, you will receive an error message like the one shared above in the overview and if you edited to allow, then the upload should go through as intended.
NOTE: It is NOT advisable to enable extensions capable of executing back-end code as this could lead to malicious files being uploaded.