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Why can’t I access the HMS/EMS Web Client (HTTP 503 or “Service Unavailable”)?

Learn how to quickly identify whether the issue is local to your PC, your network, or the WISE Helideck or Environmental Monitoring system, and what information to provide if you need to contact support.

Overview

If you can’t access the WISE Web Client (such as A+D, HMS, EMS, or DADAS) and see messages like HTTP 503 – Service Unavailable, “This site can’t be reached,” or just a blank page, this guide will help you find the most likely cause and what to do next.
Most access issues fall into one of three categories:
  • A local PC or browser issue
  • A network or DNS issue
  • A temporary service issue on the WISE system

Common symptoms

You may experience one or more of the following:
  • HTTP 503 / 502 / 504 error in the browser
  • Browser reports “Server not responding.”
  • Web client loads partially or stops responding.
  • Web access works intermittently.

Quick checks (2 minutes)

Before you try anything else, check these things first:
  1. Is the problem affecting everyone or just you?
    • Ask a colleague to try from another PC on the same network.
  2. Has the web client worked on this installation before?
    • If this is your first time using it, keep in mind that some configuration or access rules might not be set up yet.
  3. Has anything changed recently?
    • Common causes include Windows updates, changes to the firewall, server maintenance, or network updates.

Step 1: Check if the issue is local to your PC

If the issue only affects one PC:
  • Try a different browser (Chrome, Edge, Firefox).
  • Open a private / incognito window.
  • Clear the browser cache.
  • Make sure the URL is correct, including the hostname, whether it’s HTTPS or HTTP, and the port if needed.
  • Temporarily disable browser extensions or ad-blockers.
  • If possible, try on another PC in the same room or on the same network segment.
If the web client works on another PC, the issue is local.
If you still have problems, reach out to your local IT or telecom team for more help.

Step 2: Basic network checks

If multiple users are affected:
  • Try accessing the system using:
    • The normal hostname (e.g., https://wise-system-name)
    • The direct IP address (if known)
If you can access the system using the IP address but not the hostname, it’s likely a DNS issue. Your local IT or telecom team should handle this.
If neither works, continue below.

Step 3: When to contact WISE Support

Contact WISE Support if:
  • Multiple users cannot access the web client.
  • The issue persists after browser and network checks.
  • The problem affects operational use (e.g., helideck or control room visibility)
  • The issue keeps returning after a temporary fix.

Information to include when opening a support ticket

Sharing the information below will help us solve your issue much faster:
  • Asset / vessel / platform name
  • WISE system name (if known)
  • Exact error message (e.g., HTTP 503)
  • Date and time of the issue (include time zone)
  • URL used to access the web client
  • Browser and PC location (e.g., “Helideck PC”, “CCR”)
  • Screenshot showing the full browser window (including address bar)
  • Whether other users are affected

Important notes

  • Do not restart services or servers unless this is explicitly allowed by your local procedures.
  • Do not make configuration changes if you are unsure; incorrect changes can prolong downtime.
  • If helicopter or safety-critical operations are affected, escalate immediately in accordance with local procedures and notify WISE Support.