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, tried to uninstall and reinstall PostgreSQL 9.6.2 , tried to modify the config.py, config_distro.py, and delete the files in Roaming folder,i tried standalone pgadmin4 installation, but no success.However, in my local machine i am able to access the server using psql.exe and log as as superuser (postgres user). Can you please suggest any possible solutions to starting/running pgadmin4 ? Thank you.

Answer 1

I found the same issue when upgrading to pgAdmin 4 (v1.6). On Windows I found that clearing out the C:\Users\%USERNAME%\AppData\Roaming\pgAdmin folder fixed the issue for me. I believe it was attempting to use the sessions from the prior version and was failing. I know the question was marked as answered, but downgrading may not always be an option.

Note: AppData\Roaming\pgAdmin is a hidden folder.

Answer 2

We got the same issue. so no any change in the file. but start pgAdmin 4 using administrator.

The following step. 1. right click pgAdmin 4 icon 2. select "Run As Administrator"

Answer 3

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 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

if you are using Mac OS X here is a fix: Open terminal and run this command

pg_ctl -D /usr/local/var/postgres -l /usr/local/var/postgres/server.log restart

and for other OS just restart your Postgresql server, it will solve

Then start pgAdmin4, it will start as normal

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Answer 6

What finally worked was downgrading to pgadminIII-v.1.22:

Answer 7

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 8

I had same issue on windows. I had v1.6 installed as well as v2.0. Uninstalling v1.6 allowed me to login.

Answer 9

I had the same problem, but running it as an admin worked.

Answer 10

Deleting the contents of C:\Users\%USERNAME%\AppData\Roaming\pgAdmin directory worked for me!

Answer 11

Have you recently installed a new version of pgAdmin ?

This issue (and the misleading message) is simply due to the fact that old versions of pgAdmin are unable to read the settings saved by a newer version of pgAdmin !

Make sure you're starting the right version of pgAdmin (your shortcuts are likely to point to the old version !) and/or uninstall the old version: the upgrade wizard doesn't do it for you !

Answer 12

Deleting contents of folder C:\Users\User_Name\AppData\Roaming\pgAdmin\sessions helped me, I was able to start and load the pgAdmin server

Answer 13

In Windows Just go to this path and clear it ,that works !!

C:\Users\%USERNAME%\AppData\Roaming\pgAdmin

Answer 14

I was able to solve the problem by changing the pgAdmin web interface port.

I believe this problem occurred on my computer because I have several other services consuming webs ports like qBittorrent, IDEJetbrains, etc.

Right-clicking on the pgAdmin logo near the clock is possible to configure it.

Answer 15

I Fixed it in windows 10 just running pgAdmin 4 as Run as Administrator .

Answer 16

If you use older postgresql version like 9.x and its services is running,PgAdmin 4 confused which server is base database.

So stop the service older version or new one.Run PgAdmin 4 as Administrator

Its worked for me

Answer 17

I use the cmd prompt on Windows 10 with psql postgres postgres.

Then I launch pgAdmin4 and it works.

Answer 18

I had this problem with pgadmin4 v2.1 on linux fedora 27

Solved by installing a missing dependency: python3-flask-babelex

Answer 19

I had the same issue on the macosx and I renamed .pgadmin (in /users/costa) to .pgadminx and I was able to start pgAdmin4.

Answer 20

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 21

Just click on that pgadmin 4 icon and run as administrator. Allow the access permissions. It will start locally.

Answer 22

If none of the methods help try checking your system and user environments PATH and PYTHONPATH variables.

I was getting this error due to my PATH variable was pointing to different Python installation (which comes from ArcGIS Desktop).

After removing path to my Python installation from PATH variable and completely removing PYTHONPATH variable, I got it working!

Keep in mind that python command will not be available from command line if you remove it from PATH.

Answer 23

Got this issue after I upgraded PostgreSQL 9.4 to 9.6. The 9.4 binary package had PgAdmin 3 while 9.6 came with PgAdmin 4. I resolved it after a clean installation (I completely uninstalled and reinstalled) of PostgreSQL.

However, under different circumstances, you could try running the pgAdmin 4 application as an Administrator. This should fix the error.

Answer 24

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

Answer 25

I need to add this here because I've had several issues with this message. If you have recently upgraded to High Sierra you will find the latest (pgadmin 4.20) will keep appearing with the message "Application Server Could Not be Contacted". What this actually means on Macs is that python was unable to configure your environment in ~/.pgadmin

This directory stores all the things you setup and configure and even logs of what was ran on your user copy usage of pgadmin.

The way to fix this issue on High Sierra is down to sqlite3. If you look in that directory you'll see everything is stored in sqlite3 files.

When version 4.20 of pgadmin was released it was shipped with a version later than sqlite3.19 and the problem arises because High Sierra is shipped with sqlite3.19, so to fix this issue, you need to replace the old version of sqlite3 with the latest on your packager.

Now be aware, MacosX+ all use sqlite to store details for the majority of apps on your mac, so you'll need to make sure you do not just wipe the old version but you'll have to have both versions co-existing together in harmony to avoid anything major occurring on your mac.

1) download brew https://brew.sh/

2) update brew and upgrade brew to make sure it's up-to-date

3) brew install sqlite3

4) mv /usr/bin/sqlite3 /usr/bin/sqlite3.os

5) ln -s /usr/local/Cellar/sqlite/3.21.0/bin/sqlite3 /usr/bin/sqlite3

6) /usr/bin/sqlite3 -version (check version is later than 3.19)

You can now proceed to open up pgadmin as normal

Answer 26

For my case in Windows 10 for postgresql 10 version, it worked by changing SERVER_MODE to False in config_distro.py placed in web folder, as per these configuration settings: https://www.pgadmin.org/docs/pgadmin4/dev/desktop_deployment.html.

There are other settings mentioned in this answer (https://superuser.com/a/1131964) regarding python but I just changed SERVER_MODE and it worked.

Answer 27

Kill it in Windows Task Manager and then try again. It seems that there is some sort of a problem when accessing the server from different applications.

Answer 28

As for me on windows 2012r2 it's start to work only after I reinstall pgAdmin 4 to folder c:\pgAdmin4. With out spaces and any special chars. And all so I give full permission to this folder in NTFS.

Answer 29

It worked for me after installing python2.7 for pgAdmin 4 v2

Answer 30

Happens mostly when you have multiple versions of pgadmin installed or while trying to upgrade. Even I tried everything from killing the "running PID on port 5432" to "changing the server mode". In my case I uninstall postgres and re-install it again on different port(5433). Later, I opened it through cmd(right click on cmd and select "run cmd as an Administrator").