# 503 Error **URL:** \ **Category:** ADS-B Flight Tracking\ **Created:** [October 21, 2026, 3:21pm UTC](https://discussions.flightaware.com/t/503-error/100864 "2026-10-21T15:21:15Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![hajami](https://sea1.discourse-cdn.com/flex019/user_avatar/discussions.flightaware.com/hajami/32/137076_2.png) [@hajami](https://discussions.flightaware.com/u/hajami)\ **Post date:** [October 21, 2026, 3:21pm UTC](https://discussions.flightaware.com/t/503-error/100864/1 "2026-10-21T15:21:15Z")
Overnight Flighaware started showing that my Pi ADS receiver was offline. Web portal shows offline, but the PiAware portal shows it running ok and sending data. When I checked the local page at IP:8754, it’s showing a Disconnected (http\_error:503) status for the FR24 Link. Any ideas what could be causing this? ---
**Author:** ![tomvdhorst](https://sea1.discourse-cdn.com/flex019/user_avatar/discussions.flightaware.com/tomvdhorst/32/137059_2.png) [@tomvdhorst](https://discussions.flightaware.com/u/tomvdhorst)\ **Post date:** [October 21, 2026, 4:40pm UTC](https://discussions.flightaware.com/t/503-error/100864/2 "2026-10-21T16:40:44Z")
A 503 error indicates that the remote server isn’t reachable. Either the server is down of overloaded with traffic, there are a lot of reasons why you get a 503 error. I had the same issue on 3 of my sites but meanwhile they are all back-up again. Since there is/was a big issue with PHP today all over the world my guess would be that there was a lot of traffic towards the sites in general. If you want to read more on that see this link as one of the many examples: > **[Critical security issue affecting PHP](https://www.ncsc.gov.uk/news/critical-security-issue-affecting-php)** > > Updated: The NCSC is encouraging UK organisations to take immediate action to mitigate a security issue affecting PHP (CVE-2026-109618 and CVE-2026-109619). I’ve seen loads of websites being taken offline today I suspect that was also the case for some intermediate servers or even FR24 servers (but I can’t be sure since I don’t know if they run PHP). 70% of the websites worldwide run it so I wouldn’t be surprised. ---
**Author:** ![hajami](https://sea1.discourse-cdn.com/flex019/user_avatar/discussions.flightaware.com/hajami/32/137076_2.png) [@hajami](https://discussions.flightaware.com/u/hajami)\ **Post date:** [October 21, 2026, 7:18pm UTC](https://discussions.flightaware.com/t/503-error/100864/3 "2026-10-21T19:18:02Z")
Thank you for the reply and information. Looks like whatever the issue was, it’s resolved now and Flightaware is showing as online. ---
**Author:** ![Socrammmfreitas](https://sea1.discourse-cdn.com/flex019/user_avatar/discussions.flightaware.com/socrammmfreitas/32/137080_2.png) [@Socrammmfreitas](https://discussions.flightaware.com/u/Socrammmfreitas)\ **Post date:** [October 21, 2026, 8:39pm UTC](https://discussions.flightaware.com/t/503-error/100864/4 "2026-10-21T20:39:22Z")
For part of the morning and afternoon, I received a notification on my status page: "Site 228596 1. 13% of UDP multilateration traffic sent by piaware is not reaching the FlightAware servers. This may indicate a network problem." Is there any correlation? ---
**Author:** ![tomvdhorst](https://sea1.discourse-cdn.com/flex019/user_avatar/discussions.flightaware.com/tomvdhorst/32/137059_2.png) [@tomvdhorst](https://discussions.flightaware.com/u/tomvdhorst)\ **Post date:** [October 21, 2026, 9:08pm UTC](https://discussions.flightaware.com/t/503-error/100864/5 "2026-10-21T21:08:49Z")
If the issue persistant then it might be correlated to a network issue somewhere upstream, so it isn’t always inside your span of control (your own network) . Usually the percentage message is a temporary hickup in the traffic routing towards the server.