Masking issues

I keep getting getting this 'GridTools Server inaccessible' error when attempting to set up data masking:

Does anybody have any idea what is causing this issue?

Does anybody have any idea what is causing this issue?
This is the Portus discussion forum
https://cloud.ostiasolutions.com/portal/forum/
https://cloud.ostiasolutions.com/portal/forum/viewtopic.php?f=38&t=45