I recently installed a new DB server (Linux Jessie, postgres 9.4) and wanted to connect via pgAdmin 3 (1.18) and got the message that it was not supported. As I intend to upgrade the other servers in the near future, and knowing that it is recommended to move to pgAdmin4, I installed and set up my old servers (Debian Squeeze, postgres 9.1). The configuration went well I could immediately connect.
I can navigate the tree on the left with no problem and when I select a DB I receive notification that it connects (green bars on the right)
However, when I drill down to a table, select it and select the properties or SQL tabs, I get “Connection to the server has been lost”. Dashboard shows updated information statistics and dependencies are okay.
On the new server, the properties and sql are shown correctly.