Permission Violation: You need the "Allow JS/HTML Uploads" permission to access this page. Please contact your account administrator." when sending an email.

In 2018.2, NetSuite implemented a stricter policy for uploading files with suffixes .js and .html to the file cabinet so you might encounter the "Permission Violation: You need the 'Allow JS/HTML Uploads' permission to access this page. Please contact your account administrator." error when uploading a file or even when sending emails with HTML attachment using a Custom Role.

To address this issue, using an Administrator role:

1. Navigate to Setup > Users/Roles > Manage Roles.
2. Click 'Edit' beside the affected role.
3. Under "Permissions" tab, "Setup" subtab, add 'Allow JS/HTML Uploads' permission.
4. Click 'Save'.

However, if the affected user is using an Employee Center role which is not possible to be edited, you'll need to add the permission as a Global Permission. To do that, using an Administrator role:

1. Navigate to Lists > Employees > Employee.
2. Click 'Edit' beside the affected Employee's Employee record.
3. Under Access tab, Global Permissions subtab, add "Allow JS / HTML Uploads" permission.
4. Click 'Save'.