What happens when you try?
What method are you using? App or browser? Mobile, classic or desktop?
Are you using the "contact" link in a listing, or replying to an eBay message?
Try using a different browser or a different browser mode.
Try going to the seller's feedback or profile page and using the "contact" link there. If prompted for an item number, choose a current listing or "not about an item".
Or if you have eBay messages sent to your email inbox, try replying directly to the email rather than using the blue reply button in the message itself.
Or try signing in to ebay.ca, and sending a message through that site instead of ebay.com.
