Web Client Install – Fatal Error During Installation 1603

This issue relates to the failure of the Web Client install which gives the error ‘Fatal Error During Installation’ – (see error logs – code 1603)

I’ve had this issue occur a few times for NAV 2013 R2, NAV 2015 and NAV 2016.

For this particular error (1603) it turned out the Windows Firewall had been disabled – which caused the install failure.

The installer was trying to add some firewall rules but threw an error due to the firewall being disabled. Once it was re-enabled the install went through smoothly.


I tried the following to try and resolve the issue to no avail –

  • Re-installed IIS
  • Re-installed Dot.NET from scratch (bad move as the GUI got disabled)
  • Ensure ASP was installed.
  • Re-installed NAV multiple times with different admin rights.

So in summary the solution is – Enable your Windows Firewall

Fatal Error 1603

Note: The error log led me down the wrong path saying the ‘Prerequisite Powershell 3.0 wasn’t installed’ which it was.

1603 Failure

I hope this helps someone else as it had me stumped for a while.


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Andy, Software Engineer

Andy is Software Engineer at Metaphorix