topic Re: Sidebar app doesn't load in FireFox but loads in Chrome and Edge in ArcGIS Instant Apps Questions

Sidebar app doesn't load in FireFox but loads in Chrome and Edge

MappyIan — Thu, 17 Apr 2025 12:03:42 GMT

I've created a publicly accessible Sidebar app which works fine in Chrome and Edge, but won't load in FireFox: https://edinageo.maps.arcgis.com/apps/instant/sidebar/index.html?appid=fb36b35278954b79aa65d34a20e8c94c

Does anyone know why this is? As far as I can see I'm running the lates versions of each browser:

Chrome: 135.0.7049.96 (Official Build) (64-bit)
Edge: 135.0.3179.73 (Official build) (64-bit)
FireFox: 137.0.2

The Sidebar app hasn't got anything fancy in it, just a map with a few layers and a popup etc. I created the Sidebar app from scratch today (it's not an old one that's been hacked/edited over time). I've been nowhere near the JSON, all editing was done through the AGOL interface.

I'm completely stumped. If anyone can help me out I'd be very grateful.

Re: Sidebar app doesn't load in FireFox but loads in Chrome and Edge

SarahNoakes1 — Thu, 17 Apr 2025 13:02:19 GMT

Hello,

It's working for me in Firefox v137.0.1:

Re: Sidebar app doesn't load in FireFox but loads in Chrome and Edge

MappyIan — Thu, 17 Apr 2025 13:26:03 GMT

Thanks @SarahNoakes1, that's good to know. I see you're using a slightly different version of FireFox so maybe it's my machine or maybe it's something to do with the FireFox version. If anyone can load it using the same (latest) version of FireFox that I'm running I'd be interested to hear from you.

Interestingly, I can get the app to load if I use a private window in FireFox.

Re: Sidebar app doesn't load in FireFox but loads in Chrome and Edge

SarahNoakes1 — Thu, 17 Apr 2025 13:37:21 GMT

It might be caching something - have you tried clearing the cache in Firefox?

Re: Sidebar app doesn't load in FireFox but loads in Chrome and Edge

MappyIan — Thu, 17 Apr 2025 13:40:47 GMT

You're absolutely right, it was a local caching issue. No idea why I didn't think of that, I blame bank holiday brain kicking in early! Thanks again.

Re: Sidebar app doesn't load in FireFox but loads in Chrome and Edge

Molly_Ingenmey — Fri, 14 Nov 2025 18:08:37 GMT

I am also having issues with the sidebar app in firefox. I tried clearing my cache but that didn't work. Are you still having this issue at all? What version of firefox are you working with now? It loads fine on other browers, but when I try to get it to load it won't and shows this above the app:

Re: Sidebar app doesn't load in FireFox but loads in Chrome and Edge

SarahNoakes1 — Mon, 17 Nov 2025 10:08:08 GMT

Hi @Molly_Ingenmey - I have a new issue with Firefox not showing sublayers of grouped layers in my Experience Builder site. I think it's occurred since the October update so I've logged a call with ESRIUK.

Re: Sidebar app doesn't load in FireFox but loads in Chrome and Edge

LeonS — Tue, 18 Nov 2025 12:22:25 GMT

I'm having the same issue with the Sidebar instant app in Firefox. I also cleared the cache with no success. I see Firefox just recently updated to version 145.0. I wonder if its related to that.

Leon