Upgraded zoo, client does not longer retrieve license

Hi,

I just upgraded my two R5 licenses to R6. In the process I also needed to upgrade the Zoo administrator. The validation went through just fine, but now the clients are not able to retrieve licenses. Neither R5 nor R6. How do I fix this?

I would suggest run the Zoo Diagnostic Utility on the workstations to troubleshoot the connection:
https://wiki.mcneel.com/zoo/diagnostics

The Wiki page describes 5 tests and what the likely issue is for each test that fails.