Rajeev Pentyala – Dynamics 365 Blog

The other day I was getting “Invalid file name” error when I try to create an attachment with .pdf file and associating to Email, in my plug-in. (link)

Reason

• Reason was “pdf” was added as blocked file extension for attachments in my CRM organization.

Fix :-

• Go to “Settings -> Administration -> System Settings”
• Remove pdf from “Blocked file extension for attachment”

Blocked file extensions

• Click ‘OK’

🙂