pgadmin4 : postgresql application server could not be contacted.

Question

I have installed PostgreSQL 9.6.2 on my Windows 8.1. But the pgadmin4 is not able to contact the local server. I have tried several solutions suggested here in stackoverflow

Answer 1

I've been dealing with this for awhile (frustrating). So much that I have instructions on my desktop consolidating all of these ideas. Here is my magic combination to the solution:

1. Delete from App Data C:\Users\%USERNAME%\AppData\Roaming\pgAdmin
2. Add to Path Variables C:\Program Files\PostgreSQL\9.6\bin (I actually added it to both user and system)
3. Right click and start as admin.

You don't have to do this every time but when it gets out of wack try these steps.

Answer 2

I had the same issue on Windows 10, with a new installation of PostgreSQL 10.

I solved it by including the path C:\PostgreSQL\10\bin ({your path to postgresql}\bin) to system environment variables.

To access environment variables: Control Panel > System and security > System or right click on PC, then > Advance system settings > Environment variables > System variables > Path > Edit.

Answer 3

This is often a firewall problem. The firewall log then shows dropped packets between 127.0.0.1: and 127.0.0.1:, where the latter is the port shown in the Browser to get no connection with. This means, that the connection between pgAdmin client (high_port_1) and pgAdmin server (high_port_2) is blocked. Check your firewall log and if you find dropped packets like described, adapt your firewall settings accordingly.

Answer 4

It seems in most of the cases Postgres trying to use information from previous sessions to find/connect the server and failing. Clearing out the previous session info helped me, it is a combination of 2 already mentioned answers above:

1. Navigate to Postgres session's folder "C:\Users\YourUsernameOrAdmin\AppData\Roaming\pgAdmin\sessions"
2. Delete all the data from this folder.
3. Start PgAdmin in administrator mode.

Cheers!

Answer 5

I ran into this issue as well. Windows 10. I had older version of pgAdmin 4 (1.6) and 2.0. I guess both are older now.

In any case a complete uninstall of both versions and a reinstall of 2.0 worked.

Answer 6

downloaded pgadmin 4 v2.0 and install it no problem atm on force installation. try it. that was solution for me.