Forum Discussion
Add-ins not working
Hi team,
I am unable to use Add-ins. I have used two AI chatbots to troubleshoot and understand the issue, and I spoke to two Microsoft support people, the second of whom advised me to raise the issue here.
I believe it to be a server-side issue as I tried to use https://marketplace.microsoft.com/en-gb/ to re-install the add-in that I need, and the first few times I tried I got a 502 bad gateway error. However, I now don't get this error but the problem still isn't solved as I can't use add-ins.
I tried using my PC-installed copies of Word and Excel to use add-ins, and the online Word platform, and I get the same error every time - "We couldn't connect to the '{0}' catalog server".
For a while I thought the issue might be because my country was incorrectly set to the US but I eventually managed to change it to the UK and the problem is not solved.
I have troubleshot a range of solutions including to do with my internet connection and VPN - these don't seem to be the problem.
Please help.
Best wishes.
3 Replies
Seems a well-known issue:
- Catalog service outage or instability: Microsoft AppSource or the Office Add-ins catalog may be temporarily unavailable. The unresolved {0} placeholder in the error message indicates a platform-level issue rather than a specific add-in.
- Account-level restrictions: Some Microsoft 365 Personal/Family accounts may have limited access to the catalog.
- Privacy settings: If Connected Experiences are disabled, Office cannot connect to the catalog.
- Network/security filters: VPNs, proxies, ad blockers, or strict firewall rules can block catalog connections.
Hey there,
That sounds incredibly frustrating – especially after already going through two Microsoft support agents and multiple troubleshooting steps.
I've actually seen this exact "{0} catalog server" error pop up in a few other threads recently, and in most cases, it does seem to be something on Microsoft's end rather than a local issue. It's interesting that you mentioned the 502 bad gateway error on the marketplace site – that's a pretty strong indicator that something's going on with their infrastructure.
One thing that worked for someone in a similar thread was clearing the Office cache and resetting the add-in registry keys, but honestly, since you're getting the same error across both desktop and web versions, I doubt that's going to help in your case. It really does point to a server-side authentication or catalog connection issue.
Have you tried checking if the add-in works from a completely different network (like using your phone hotspot instead of home/work WiFi)? I know you mentioned VPN troubleshooting, but just wanted to double-check. Sometimes it's a DNS resolution thing with the catalog servers.
Also worth a shot – if you go to File > Options > Trust Center > Trust Center Settings > Add-ins, do you see anything blocked or restricted there? Probably not, but worth ruling out.
Definitely following this because I rely on a couple of add-ins for my workflow and I'm worried about this being a broader issue. Hopefully one of the community MVPs or Microsoft folks picks this up soon – they're usually pretty responsive on these technical threads.
Keep us posted if you find a workaround, and I'll do the same if I spot anything helpful elsewhere.
Good luck mate.
Getting the same issue here. Apparently it's a region thing in my case. Here's more details.
Addins don't work on my personal account (both on the applications and the word/excel online) but they work when i use another account like my work account. This may point to an account issue but it's not. I remote my PC at home and everything works on my personal account. So it's just my personal account not working overseas. Even a VPN doesn't help
