Smalltalkhub returning 500 response for a public repository

I've been trying unsuccessfully to write to the
SandstoneDb public repository at smalltalkhub.com

http://smalltalkhub.com/#!/~gnaritas/SandstoneDb
shows the green tickmark and PUBLIC

Writing to a package within it receives a 500 error.

The specific package I am writing to is:
SandstoneDbTests
which is marked in Monticello (after I have downloaded it) as belonging in
http://smalltalkhub.com/mc/gnaritas/SandstoneDb/main

as do all the other listed packages, i.e.
ConfigurationOfSandstoneDb
SandstoneDb
SandstoneDbFileSystemStore
SandstoneDbFuel
SandstoneDbFileDirectoryStore
SandstoneDbSqueak
SandstoneGOODS
SandstondDbGOODSTests

(Thank you to Max Leske for confirming it was a 500 error at the
smalltalkhub.com end that was causing the debugger to respond to my
attempted commit).