Website errors explained

The first digit tells you who has the problem

• 4xx — your side. Your browser asked for something the server can't or won't give. Often a sign-in, permission, or wrong-URL issue. You can usually fix these.
• 5xx — the server's side. The website's server crashed, is overloaded, or can't reach a piece of itself. You generally can't fix these — wait, retry, or report them.
• 3xx — redirect. The page moved. Usually invisible. If you see one, it's normally a misconfigured redirect loop.
• 2xx — success. You'll never see one of these as an error message; it just means the page loaded.

400 — Bad Request

What it means: The server didn't understand what you sent. Often caused by old saved website data, a corrupted URL, or a browser extension breaking the request.

Try: hard-refresh the page (Ctrl+Shift+R), clear cookies for that site, or open the page in a private window. If it still fails, the URL itself may be malformed — go back to the source link.

401 — Unauthorized

What it means: The site needs you to sign in, and either you didn't, or your session expired.

Try: sign in again. If you were already signed in, sign out fully and back in. If your account uses multi-factor sign-in and your phone changed recently, see the Getting a new phone without losing multi-factor sign-in article.

403 — Forbidden

What it means: You're authenticated, but you don't have permission to see this page. The server recognizes you and is saying no.

Try: confirm you signed in with the right account (your work account, not a personal one). If it's a SharePoint or shared folder, the owner needs to grant you access. Send the URL and the time you tried to support — they can check the access list.

404 — Not Found

What it means: The page doesn't exist at that URL. Either the link is wrong, the page was renamed or deleted, or there's a typo.

Try: double-check the URL for typos. Search the site from its homepage instead. If a colleague sent you the link, ask them to send a fresh one — pages sometimes get renamed in CMS systems.

408 — Request Timeout

What it means: Your browser took too long to finish sending its request. Almost always a slow or interrupted internet connection on your side.

Try: retry in a few seconds. If on Wi-Fi, move closer to the access point or switch to wired. If you're on VPN, disconnect and reconnect.

413 — Payload Too Large

What it means: You tried to upload a file that's bigger than the website allows.

Try: compress the file (zip), upload to OneDrive/SharePoint/Box and share the link instead, or split the file. The site's help pages usually list the actual upload limit.

429 — Too Many Requests

What it means: You've hit the site too many times in a short window — usually because of a script, a plugin, or rapid clicking. The server is asking you to slow down.

Try: wait a minute and reload. If you have browser extensions that auto-refresh or scrape pages, disable them on this site.

500 — Internal Server Error

What it means: Something on the website crashed. The site's developers need to fix it; you can't.

Try: wait a few minutes and reload. If it's still broken in 15 minutes, check the vendor's status page (e.g., status.autodesk.com, status.bentley.com). Report to support with the URL, time, and a screenshot.

502 — Bad Gateway

What it means: The website got an unexpected response from part of its own service. Common during updates or when a service is restarting.

Try: wait 1–5 minutes and reload. Almost always temporary.

503 — Service Unavailable

What it means: The site's server is up but is intentionally refusing to handle your request — usually because it's overloaded or in maintenance.

Try: wait and retry. Check the vendor's status page. Don't keep refreshing aggressively — that makes overload worse.

504 — Gateway Timeout

What it means: The site's front-end waited too long for a response from a back-end service and gave up. Same family as 502 — server-side hiccup.

Try: reload after a minute. Persistent 504s usually mean a service the site depends on (database, identity, file storage) is degraded.

"This site can't be reached" / DNS_PROBE_FINISHED_NXDOMAIN

What it means: Your computer couldn't translate the website's name (like example.com) into an IP address. Either the URL is mistyped, the site is genuinely down, or your DNS is misbehaving.

Try: double-check the URL spelling. Try the site from a phone on cellular data — if that works, the problem is on your network. Restart your Wi-Fi router or reconnect to VPN. Last resort, run ipconfig /flushdns from a command prompt to clear old DNS records.

"Your connection is not private" / NET::ERR_CERT_*

What it means: The site's security certificate is missing, expired, or doesn't match the URL. This is what protects you from a fake version of the site.

Try: first, check your computer's clock — a wrong system date is the most common cause. If the date is right, do not click "Continue anyway" on a public site. For internal sites your firm runs, this can mean a certificate just expired and IT needs to renew it. For public sites, navigate away.

"Too many redirects" / ERR_TOO_MANY_REDIRECTS

What it means: The site keeps bouncing you between pages in a loop. Usually a cookie problem or a broken sign-in flow.

Try: clear cookies for that site, then reload. In Chrome/Edge: lock icon next to the URL → Cookies → remove all → close the tab and reopen.

ERR_CONNECTION_REFUSED

What it means: Your computer reached the site's server but the server flat-out refused the connection. Common when a corporate firewall blocks the site, or the service is fully offline.

Try: connect to VPN if the site is internal. Try the site from a phone on cellular — if that works, your network is blocking it. Report the URL to IT.

ERR_CONNECTION_TIMED_OUT

What it means: Your computer asked the site to respond and never got an answer. Usually a slow network, a VPN drop, or a firewall silently dropping traffic.

Try: retry. Disconnect and reconnect VPN. Switch to a different network if available.

ERR_INTERNET_DISCONNECTED

What it means: Your computer thinks it has no network at all.

Try: check that Wi-Fi is on and connected, or that your Ethernet cable is plugged in. Open Settings → Network & internet and confirm the status. If you're on Wi-Fi, forget the network and rejoin.

The 5 fixes, in order

1. Hard refresh the page (Ctrl + Shift + R on Windows / Cmd + Shift + R on Mac). Forces the browser to ignore its cached copy.
2. Open the page in a private / Incognito window. If it works there, the problem is a cookie or extension on your normal profile.
3. Try a different browser. If Chrome fails but Edge works, the cause is profile-specific.
4. Check from your phone on cellular data (turn off Wi-Fi). If it works, the problem is your network or VPN.
5. Restart your computer. Cliché, but it clears half of the weird ones — saved DNS data, network adapter state, stuck processes.

Send these details

• The full URL (copy from the address bar — don't paraphrase).
• A screenshot of the error message and any error code shown.
• The exact time it happened (helps IT find it in logs).
• What browser and what version (in Chrome/Edge: About page; or paste chrome://version in the address bar).
• Whether you're on VPN, in the office, on home Wi-Fi, or on a phone hotspot.
• Whether other people see the same error, or only you.
• Whether anything changed recently — new computer, new phone, network change, new extension.

See also: Taking screenshots for IT.