Service does not start PRTG Core Service

Hello,

thank you very much for your KB-Post!

Can you please try setting the PRTG Webserver to start on Port 80 on localhost/127.0.0.1 with the PRTG Server Admin Tool, and then try starting the Core Service again. Does it then start?

best regards.

I'm having the same issue, and I tried setting the port to 80 on localhost, and still get this error.

I had a previous installation of PRTG which stopped working at some point. I installed latest version, it still doesn't work. Also tried un-installing/re-installing, still no luck.

The only PRTG message in the windows services log file is:

- <Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event">
- <System>
  <Provider Name="PRTG Network Monitor" /> 
  <EventID Qualifiers="0">0</EventID> 
  <Level>4</Level> 
  <Task>0</Task> 
  <Keywords>0x80000000000000</Keywords> 
  <TimeCreated SystemTime="2014-05-01T06:41:14.000000000Z" /> 
  <EventRecordID>1</EventRecordID> 
  <Channel>PRTG Network Monitor</Channel> 
  <Computer>AMUSIUM</Computer> 
  <Security /> 
  </System>
- <EventData>
  <Data>Trying to restart PRTG Core Server Reason: A setting in need of a restart has been changed.</Data> 
  </EventData

Please help!

Did you try a full system reboot on the machine?

I did a hard boot, still the same issue. I revisited the logs, the message "Trying to restart PRTG Core Server Reason: A setting in need of a restart has been changed." was old.

There are no current messages in the Application and Service logs/PRTG Network Monitor. However, in the general Windows Logs/Application, I see these info entries for PRTG:

-Starting 14.4.12.3509

-Startup: Starting Core Server: PRTG Network Monitor 14.4.12.3509 x64 PRTG Network Monitor Freeware (Trial Expired, 100 Days) ID: -1000

-Core Server will shut down now (running for 1 s since 12/10/2014 2:42:34 PM) ID: -1000

-Could not start webserver: '''' is not a valid integer value ID: -1000

It looks like somehow the port number has gotten scrambled, but using the PRTG Administrator tool to set it to anything doesn't help.

The message indicates that there is likely a problem with the configuration file (it may have been corrupted).

Please try to replace your running config file;
C:\ProgramData\Paessler\PRTG Network Monitor\PRTG Configuration.dat

with one from the auto backup folder.
C:\ProgramData\Paessler\PRTG Network Monitor\Configuration Auto-Backups\

Yesterday's config or the one before should work. Please ensure that both services (PRTG Core Server and PRTG Probe) are stopped before overwriting the config file.

Please also take a look at the following KB-Article as it explaining this process:
How do I restore a previous configuration of PRTG from automated backup ZIPs?