No slaves showing available for pool assignment

We are using deadline client v2.7.29178. We have two slaves and our repository is mounted on an Apple OSX share. I am attempting to add slaves to our 3dsmax pool, however when I right click on that pool I am not given the modify pool option to assign slaves to that pool and no slaves or other network nodes appear available to be added to a pool, despite the fact that when I poll the deadline network all my slaves show up as online and are pointed to the correct repository.

Can you help?

Thanks,

John