Hi Rhona,
This error usually fires when the user is running a validation with some CT that cannot be found in our server. SEND CT 2019-03-29 should be available for all users logged in with Pinnacle ID. This error might fire if CT is added manually and app is offline (or blocked by firewall) and cannot check the server.
I would ask for some more information to better understand your issue. Could you please tell, are these users logged in with Pinnacle IDs?
Are there any known restrictions for your Internet connection that could prevent the app from getting updates?
Did these users manually add this CT file to config folder or was it downloaded automatically? The correct path for storing SEND CT 2019-03-29 would be following:
C:\Users{UserName}\Documents\Pinnacle 21 Community\configs\data\CDISC\SEND\2019-03-29
Thanks,
Philipp