topic Re: Can't download Developer app. I've never experienced this. in ArcGIS Experience Builder Questions

Can't download Developer app. I've never experienced this.

AdamGebhart — Wed, 05 Nov 2025 20:34:33 GMT

I just attempted to download and deploy an app to our local server and got the following message. I am in Developer 1.18 and have used a few older versions and never seen this until today.

I am wondering if this is related to a recent update of my PC from Windows 10 to 11. The reason I say that is I have successfully downloaded and deployed two different 1.18 apps prior to the Windows update.

Has anyone else seen this and know how to fix it?

Re: Can't download Developer app. I've never experienced this.

JeffreyThompson2 — Wed, 05 Nov 2025 20:45:54 GMT

I don't know what's going on. The first thing I would try is running the Command Prompts in Admin mode.

Re: Can't download Developer app. I've never experienced this.

AdamGebhart — Wed, 05 Nov 2025 21:17:55 GMT

I ran that as an administrator and still failed. I did notice this in the command prompt window.

I don't recall ever deleting that folder and I don't see the same folder being in 1.17 or 1.16.

Re: Can't download Developer app. I've never experienced this.

JeffreyThompson2 — Thu, 06 Nov 2025 14:07:13 GMT

This error suggests you created a custom Theme called Master at some point and then removed it. Or didn't migrate it when you updated Experience Builder. Things to try:

Add the Master Theme back to the your-extensions/themes folder with the client server off, then start the client server.
If you don't want to use this Theme anymore, check all your projects Themes and set them to something other than Master.

Re: Can't download Developer app. I've never experienced this.

AdamGebhart — Thu, 06 Nov 2025 15:43:33 GMT

@JeffreyThompson2

Hmmm, I looked back at all the versions of ExB I've downloaded or used before (1.10, 1.11, 1.14 - 1.18) and none of them have the Master folder.

This specific app is one I built in ArcGIS Online then imported into Developer. (This was the first time I've tried that workflow). Do you think there is a chance it's related to that?

Re: Can't download Developer app. I've never experienced this.

JeffreyThompson2 — Thu, 06 Nov 2025 15:53:18 GMT

Yes, I think that is the problem. Did you download after the update on Oct 23? Themes were re-designed in the last update to something incompatible with the older version of Themes. And the entire application would be a version ahead of your Developer Edition.

Re: Can't download Developer app. I've never experienced this.

AdamGebhart — Thu, 06 Nov 2025 15:55:33 GMT

Yes, that's exactly what I did. Normally I just test things out in AGO, then build everything new in Developer.

I suppose I'll test out a new Developer app in a little bit and see if I can download it.

Re: Can't download Developer app. I've never experienced this.

JeffreyThompson2 — Thu, 06 Nov 2025 16:03:04 GMT

Wait a few weeks for Developer Edition 1.19 to come out. It should be compatible with the version currently in ArcGIS Online.

Re: Can't download Developer app. I've never experienced this.

AdamGebhart — Thu, 06 Nov 2025 16:09:48 GMT

Unfortunately this app needs to be published before Developer 1.19 is released, so I have to just build all new in Develooper. It won't take too long though but I really wish I would have done it all in Developer to start.

Thanks for the suggestions.

Re: Can't download Developer app. I've never experienced this.

AdamGebhart — Thu, 06 Nov 2025 20:39:31 GMT

@JeffreyThompson2 I finished building the app in Developer 1.18 and was able to download it. I marked your comment about that as the solution. Thanks.

Re: Can't download Developer app. I've never experienced this.

Wei_Ying — Mon, 17 Nov 2025 19:21:03 GMT

Hi @AdamGebhart we have 1.19 recently released, could you try and see if the problem solved?