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PRTG's website doesn't work, tabs don't work and I am seeing lots of Javascript error messages



All interactive AJAX functions of the web interface of PRTG 8 are not working, e.g. the tabs do not work.

The Firefox error console (or the FireBug console) display numerous Javascript errors, e.g.:

Error: missing ] after element list Source File: https://x.x.x.x/javascript/prtg.js?version= Line: 9090, Column: 7 Source Code: [Error C3: Include File Not Found "javascript\prtg.refreshfunctions.js"];

Error: userIsReadOnly is not defined Source File: https://x.x.x.x/welcome.htm? Line: 476

Error: installOctopusTimer is not defined Source File: https://x.x.x.x/welcome.htm? Line: 427

error error-messages javascript web-interface

Created on Apr 18, 2011 11:18:11 AM by  Dirk Paessler [Founder Paessler AG] (11,025) 3 6

2 Replies



It looks like the whole Javascript system of your PRTG installation has been damaged.

From your description I can not tell why. But the message

[Error C3: Include File Not Found "javascript\prtg.refreshfunctions.js"]

tells us that a Javascript file is missing.

Let's try to make sure that all files are where they are supposed to be by deleting the whole "website" folder from your PRTG installation and reinstalling PRTG:

Please follow the following steps:

  • Start the PRTG Core Server Admin Tool (from PRTG's start menu group)
  • Click the "Start/Stop" tab and stop PRTG Core Server
  • Close the Core Sever Admin Tool
  • In Windows explorer navigate to the "PRTG Network monitor" folder
  • Rename the "website" subfolder in to e.g. "website2"
  • now rerun PRTG's installer which will properly re-install all necessary files for the web interface
  • this will also restart the core server for you
  • Now test the PRTG website again.


  • your monitoring and sensor configuration will not be affected by this process, you will only see a short downtime due to the installation process
  • If you have made modifications to the web GUI (e.g. added your own CSS or Javascript) you must reapply those modifications

Created on Apr 18, 2011 11:23:23 AM by  Dirk Paessler [Founder Paessler AG] (11,025) 3 6

Last change on Apr 18, 2011 11:29:30 AM by  Dirk Paessler [Founder Paessler AG] (11,025) 3 6



Thank fixed it. Thank you very much.

Created on Apr 18, 2011 1:55:04 PM

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.