Originally Posted by
The_Legend_Shall_Live_On
Hey there Down. Welcome to the forums.
This is likely a technical issue. From my experience, log out, close the game from background, log back in and wait for a minute and try again. If that does have the PvE show up, then try once more. If still no go, delete the app, reinstall, open it, then wait a minute. Its possible you have to log in and out again. (Also, don't freak out if some of your other units from events have disappeared; logging out and in again will bring them back)
If none of the above works, contact help ASAP as it is some other problem.