Unale to invole program

Hi All,

Anyone know the fix to this problem?

I have a user that’s trying to “open” pdf attachment within the message but gets that message.

It was working previously, but for some reason its now not.

Detaching the file and opening it works fine.

Got user to forward me the attachments and i can open them without any problems.

Checked all file associations through windows and look ok.

Much appreciated.

John.