Every .pdf attachment that I click on gets the same "This attachment cannot be shown at this time. Please try back later." window. This has happened over multiple days so the 'later' doesn't matter.
Nolines is correct. Due to a forced server migration, several PDF and image files are lost in limbo. Is this a new file you are having issues with @ronaconda or older ones? Member @shues has had some success in finding older ones on the "Wayback Machine" website