I’m trying to logon to the Omeka S sandbox, but get the following error:
Omeka S encountered an error
To learn how to see more detailed information about this error, see the Omeka S User Manual page on retrieving error messages.
I’ve been using the following URL to enter the sandbox, without issues so far:
http://dev.omeka.org/omeka-s-sandbox/login
Thank you very much in advance 
It should be fine now.
It does!
Thanks.
What was the problem?
(As soon-to-be sysadmin of an Omeka S instance, I’m of course curious what can cause an instance to be unavailable like that )
This one isn’t so much something you’d be likely do deal with: we do a variety of things with the server that hosts the sandbox, and we just let it run out of disk space accidentally. This combined with the sandbox-specific system where it gets periodically reset caused the issue you saw.
Get it.
Thanks for the insights! 