title: The pgAdmin 4 server could not be contacted: Fatal error
body: <p>I upgrade PostgreSQL from 13.3 to 13.4 and got a fatal error by pgAdmin 4. I found other similar question that try to fix the problem deleting the folder: &quot;C:\Users\myusername\AppData\Roaming\pgadmin\sessions&quot; and running pgAdmin as admin but nothing happen. Also i completely remove postgres and reinstall it, and i installed pgAdmin with his separate installation, but nothing happen again.
  This is the error:</p>
  <pre><code>pgAdmin Runtime Environment
  --------------------------------------------------------
  Python Path: &quot;D:\Program Files\PostgreSQL\13\pgAdmin 4\python\python.exe&quot;
  Runtime Config File: &quot;C:\Users\Alessandro\AppData\Roaming\pgadmin\runtime_config.json&quot;
  pgAdmin Config File: &quot;D:\Program Files\PostgreSQL\13\pgAdmin 4\web\config.py&quot;
  Webapp Path: &quot;D:\Program Files\PostgreSQL\13\pgAdmin 4\web\pgAdmin4.py&quot;
  pgAdmin Command: &quot;D:\Program Files\PostgreSQL\13\pgAdmin 4\python\python.exe -s D:\Program Files\PostgreSQL\13\pgAdmin 4\web\pgAdmin4.py&quot;
  Environment: 
    - ALLUSERSPROFILE: C:\ProgramData
    - APPDATA: C:\Users\Alessandro\AppData\Roaming
    - CHROME_CRASHPAD_PIPE_NAME: \\.\pipe\crashpad_6172_IWUHMIZQAVFZRPVX
    - CHROME_RESTART: NW.js|Spiacenti, si è verificato un arresto anomalo di NW.js. Riavviarlo ora?|LEFT_TO_RIGHT
    - CommonProgramFiles: C:\Program Files\Common Files
    - CommonProgramFiles(x86): C:\Program Files (x86)\Common Files
    - CommonProgramW6432: C:\Program Files\Common Files
    - COMPUTERNAME: HP820G1-ALESSAN
    - ComSpec: C:\WINDOWS\system32\cmd.exe
    - DriverData: C:\Windows\System32\Drivers\DriverData
    - FPS_BROWSER_APP_PROFILE_STRING: Internet Explorer
    - FPS_BROWSER_USER_PROFILE_STRING: Default
    - HOMEDRIVE: C:
    - HOMEPATH: \Users\Alessandro
    - JD2_HOME: D:\Program Files\JDownloader2
    - JDK_HOME: D:\Program Files\Java\jdk-16.0.2
    - LOCALAPPDATA: C:\Users\Alessandro\AppData\Local
    - LOGONSERVER: \\HP820G1-ALESSAN
    - NUMBER_OF_PROCESSORS: 4
    - OneDrive: D:\temp\OneDrive - Università di Salerno
    - OneDriveCommercial: D:\temp\OneDrive - Università di Salerno
    - OS: Windows_NT
    - Path: D:\Program Files\Python39\Scripts\;D:\Program Files\Python39\;C:\Program Files\Common Files\Oracle\Java\javapath;C:\WINDOWS\system32;C:\WINDOWS;C:\WINDOWS\System32\Wbem;C:\WINDOWS\System32\WindowsPowerShell\v1.0\;C:\WINDOWS\System32\OpenSSH\;D:\Program Files\UltraEdit;C:\Program Files\Intel\WiFi\bin\;C:\Program Files\Common Files\Intel\WirelessCommon\;D:\Program Files\MATLAB\R2021a\bin;D:\Program Files\mingw-w64\x86_64-8.1.0-posix-seh-rt_v6-rev0\mingw64\bin;D:\Program Files\Zerynth\ztc\windows64;D:\Program Files\PostgreSQL\13\bin;C:\Users\Alessandro\AppData\Local\Microsoft\WindowsApps;D:\Program Files\Java\jdk-16.0.2;C:\Program Files\Intel\WiFi\bin\;C:\Program Files\Common Files\Intel\WirelessCommon\;D:\Program Files\Microsoft VS Code\bin;D:\Program Files\mingw-w64\x86_64-8.1.0-posix-seh-rt_v6-rev0\mingw64\bin;D:\Program Files\JetBrains\PyCharm Community Edition 2021.1.1\bin;C:\Users\Alessandro\zerynth3\dist\sys\cli;D:\Program Files\PostgreSQL\13\bin;
    - PATHEXT: .COM;.EXE;.BAT;.CMD;.VBS;.VBE;.JS;.JSE;.WSF;.WSH;.MSC;.PY;.PYW
    - PGADMIN_INT_KEY: 89448562-228e-4522-bc29-54d857da3f2a
    - PGADMIN_INT_PORT: 55190
    - PGADMIN_SERVER_MODE: OFF
    - PROCESSOR_ARCHITECTURE: AMD64
    - PROCESSOR_IDENTIFIER: Intel64 Family 6 Model 69 Stepping 1, GenuineIntel
    - PROCESSOR_LEVEL: 6
    - PROCESSOR_REVISION: 4501
    - ProgramData: C:\ProgramData
    - ProgramFiles: C:\Program Files
    - ProgramFiles(x86): C:\Program Files (x86)
    - ProgramW6432: C:\Program Files
    - PSModulePath: C:\Program Files\WindowsPowerShell\Modules;C:\WINDOWS\system32\WindowsPowerShell\v1.0\Modules
    - PUBLIC: C:\Users\Public
    - PyCharm Community Edition: D:\Program Files\JetBrains\PyCharm Community Edition 2021.1.1\bin;
    - SESSIONNAME: Console
    - SystemDrive: C:
    - SystemRoot: C:\WINDOWS
    - TEMP: C:\Users\ALESSA~1\AppData\Local\Temp
    - TMP: C:\Users\ALESSA~1\AppData\Local\Temp
    - USERDOMAIN: HP820G1-ALESSAN
    - USERDOMAIN_ROAMINGPROFILE: HP820G1-ALESSAN
    - USERNAME: Alessandro
    - USERPROFILE: C:\Users\Alessandro
    - windir: C:\WINDOWS
  --------------------------------------------------------
  
  Traceback (most recent call last):
    File &quot;D:\Program Files\PostgreSQL\13\pgAdmin 4\web\pgAdmin4.py&quot;, line 39, in &lt;module&gt;
      import config
    File &quot;D:\Program Files\PostgreSQL\13\pgAdmin 4\web\config.py&quot;, line 25, in &lt;module&gt;
      from pgadmin.utils import env, IS_WIN, fs_short_path
    File &quot;D:\Program Files\PostgreSQL\13\pgAdmin 4\web\pgadmin\__init__.py&quot;, line 24, in &lt;module&gt;
      from flask_socketio import SocketIO
    File &quot;D:\Program Files\PostgreSQL\13\pgAdmin 4\python\lib\site-packages\flask_socketio\__init__.py&quot;, line 9, in &lt;module&gt;
      from socketio import socketio_manage  # noqa: F401
    File &quot;D:\Program Files\PostgreSQL\13\pgAdmin 4\python\lib\site-packages\socketio\__init__.py&quot;, line 9, in &lt;module&gt;
      from .zmq_manager import ZmqManager
    File &quot;D:\Program Files\PostgreSQL\13\pgAdmin 4\python\lib\site-packages\socketio\zmq_manager.py&quot;, line 5, in &lt;module&gt;
      import eventlet.green.zmq as zmq
    File &quot;D:\Program Files\PostgreSQL\13\pgAdmin 4\python\lib\site-packages\eventlet\__init__.py&quot;, line 17, in &lt;module&gt;
      from eventlet import convenience
    File &quot;D:\Program Files\PostgreSQL\13\pgAdmin 4\python\lib\site-packages\eventlet\convenience.py&quot;, line 7, in &lt;module&gt;
      from eventlet.green import socket
    File &quot;D:\Program Files\PostgreSQL\13\pgAdmin 4\python\lib\site-packages\eventlet\green\socket.py&quot;, line 21, in &lt;module&gt;
      from eventlet.support import greendns
    File &quot;D:\Program Files\PostgreSQL\13\pgAdmin 4\python\lib\site-packages\eventlet\support\greendns.py&quot;, line 401, in &lt;module&gt;
      resolver = ResolverProxy(hosts_resolver=HostsResolver())
    File &quot;D:\Program Files\PostgreSQL\13\pgAdmin 4\python\lib\site-packages\eventlet\support\greendns.py&quot;, line 315, in __init__
      self.clear()
    File &quot;D:\Program Files\PostgreSQL\13\pgAdmin 4\python\lib\site-packages\eventlet\support\greendns.py&quot;, line 318, in clear
      self._resolver = dns.resolver.Resolver(filename=self._filename)
    File &quot;D:\Program Files\PostgreSQL\13\pgAdmin 4\python\lib\site-packages\dns\resolver.py&quot;, line 543, in __init__
      self.read_registry()
    File &quot;D:\Program Files\PostgreSQL\13\pgAdmin 4\python\lib\site-packages\dns\resolver.py&quot;, line 720, in read_registry
      self._config_win32_fromkey(key, False)
    File &quot;D:\Program Files\PostgreSQL\13\pgAdmin 4\python\lib\site-packages\dns\resolver.py&quot;, line 674, in _config_win32_fromkey
      self._config_win32_domain(dom)
    File &quot;D:\Program Files\PostgreSQL\13\pgAdmin 4\python\lib\site-packages\dns\resolver.py&quot;, line 639, in _config_win32_domain
      self.domain = dns.name.from_text(str(domain))
    File &quot;D:\Program Files\PostgreSQL\13\pgAdmin 4\python\lib\site-packages\dns\name.py&quot;, line 889, in from_text
      return from_unicode(text, origin, idna_codec)
    File &quot;D:\Program Files\PostgreSQL\13\pgAdmin 4\python\lib\site-packages\dns\name.py&quot;, line 852, in from_unicode
      raise EmptyLabel
  dns.name.EmptyLabel: A DNS label is empty.
  </code></pre>
  <p>I don't understand why a DNS Problem is raised, anyone has suggestion or fix?
  Thanks.</p>