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Probe Service or Core Service stop working after updating from PRTG 8 to PRTG 9 or later



After updating from version 8 to the current version of PRTG Network Monitor either the core server process or a probe have problems with the web server or monitoring tasks , e.g. they can not connect to systems beyond an ISA server (or similar firewall). Or one of the services doesn't start at all.

What could be the cause of the troubles?

probe prtg prtg12 prtg9 remote-probe service setup

Created on Sep 28, 2011 8:17:57 AM by  Dirk Paessler [Founder Paessler AG] (11,025) 3 6

Last change on May 9, 2012 12:15:08 PM by  Daniel Zobel [Product Manager]

1 Reply

Accepted Answer



Important note: The information in this article is outdated. We do not officially support any updates from PRTG 7 or PRTG 8! It is also technically not possible to directly update from these versions to current PRTG versions. We recommend that you perform a clean installation of the latest PRTG version.

Please see PRTG Manual: Update From Previous Versions

1. Did the new PRTG installer suggest a reboot and you did not accept to do that?

The installer only suggests a reboot, if it is absolutely necessary. So you must follow this recommendation! Please reboot.

2. Did the PRTG 8 services run under a specific user account before the update?

During an update-installation from V7/8 to V9 or later, the PRTG installer sets the account for the services to "Local System".

  • We first deinstall the old "PRTG Probe Service" (Windows NT service "PRTG7ProbeService") and
  • then we reinstall the new "PRTG Probe Service" (Windows NT service "PRTGProbeService")
  • we first deinstall the old "PRTG Core Server Service" (Windows NT service "PRTG7CoreService") and
  • then we reinstall the new "PRTG Probe Service" (Windows NT service "PRTGCoreService")

If the old services were running under a specific user account (e.g. this is required for Internet access in a network controlled by ISA server) this user account setting is lost during the transition.

Please open the service manager and reapply the user account settings.

3. No, this was not the cause for the problems

  • Do you run Windows 2003 Server without Service Packs or very old Service Packs? Please update to the latest available service pack.
  • Please have a look at the most recent entries at the bottom of the “PRTG Core Server Log” and “PRTG Probe Log”. You may find hints for whats going wrong there.

4. No, this did not help either

If this doesn’t help

  • Please open the Paessler registry key in the registry editor (regedit) and export it into a .reg file (context menu => export)
  • Key for 32-bit: HKEY_LOCAL_MACHINE\SOFTWARE\Paessler\
  • Key for 64-bit: HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Paessler
  • Send this .reg file together with all log files from the “Logs (System)” Folder to Paessler for analysis

5. The last resort: Creating a new config from scratch

An approach that may help to get everything running again is the following:

  • Stop all PRTG services
  • Delete the Paessler registry key using the regeditor
  • Rename the data folder (default is %ALLUSERSPROFILE%\Application data\Paessler\PRTG Network Monitor)
  • Reboot (this will restart PRTG services)
  • PRTG should now start with a clean default configuration (i.e. you can access the web interface and log in)
  • If it does not start:
    • check the “PRTG Core Server log” file. There are serious problems.
  • If it does start: We will now try to switch to your previous configuration
    • Stop both services again
    • Open the Core Server Admin Tool
    • edit the Data Folder to the renamed folder of your old data
    • and review all other settings in the admin tool
    • Upon exiting the admin tool the core server service is restarted
    • Start the probe service manually
  • Now you should be running your old configuration in the current PRTG version.

If all this doesn't help, please open a support ticket.

Created on Sep 28, 2011 8:23:04 AM by  Dirk Paessler [Founder Paessler AG] (11,025) 3 6

Last change on Sep 8, 2015 4:22:08 PM by  Gerald Schoch [Paessler Support]

Disclaimer: The information in the Paessler Knowledge Base comes without warranty of any kind. Use at your own risk. Before applying any instructions please exercise proper system administrator housekeeping. You must make sure that a proper backup of all your data is available.