v17: uSync Template Import Fails with “Failed to create template” on Umbraco 17.5.3

[gohil-chetan]

I am facing an issue with importing a template using uSync on our production/IIS environment.

Environment
Umbraco: 17.5.3
uSync: 17.3.6
Hosting: IIS
Runtime Mode: Production
ModelsBuilder: Nothing

I created a new template locally and the uSync import works successfully on my local environment.

However, after publishing the code and hosting the application on IIS, the same uSync import fails when I try to import the template.

Configuration

The relevant appsettings.json configuration is:

"Umbraco": {
"CMS": {
"Runtime": {
"Mode": "Production"
},
"Global": {
"UseHttps": true
},
"ModelsBuilder": {
"ModelsMode": "Nothing"
},
"WebRouting": {
"UmbracoApplicationUrl": "https://<REPLACE_WITH_YOUR_PRIMARY_DOMAIN>/"
}
}
}
Error

The uSync API returns the following response:

{
"handlerAlias": "TemplateHandler",
"success": false,
"itemType": "ITemplate",
"message": "Failed to create template",
"exception": null,
"change": "Import",
"fileName": "Single Item 4537ecd6-4518-4054-bfe7-1d8344d88c67",
"name": "LinkTreeNew",
"path": null,
"requiresPostProcessing": true,
"detailMessage": null,
"details": null,
"key": "4537ecd6-4518-4054-bfe7-1d8344d88c67"
}

The template name is LinkTreeNew.

We are using docker to deployment process.

Could you please help us identify why the template import is failing on the IIS/production environment?

Is there any additional configuration, permission, runtime setting, or uSync setting required for template imports in Umbraco 17.5.3 / uSync 17.3.6 when running in Production mode on IIS?

Please also let us know if there are any logs or additional debugging steps we should enable to get the underlying exception causing “Failed to create template.”

Thank you.

[KevinJump]

Yes, need to check there hasn't been any changes to the behavior in production pushing recently, but uSync does (should) support that.

At the moment the line that is returning the error is swallowing the status from the TemplateService so it doesn't give you a way to find it. (although its likely duplicate alias?).

but we will do some production checks before we push a update out with better logging,

[gohil-chetan]

Thanks @KevinJump .

I have also tried upgrading both the Umbraco version and uSync version and then hosted the updated application on IIS. However, I am still getting the same “Failed to create template” error that I shared above.

I have verified that the template imports successfully in the local environment, but the issue persists after deployment to IIS.

Could you please investigate this and advise if there is any additional configuration required for Umbraco 17/uSync when running in Production mode on IIS?

[KevinJump]

Hi,

Just to confirm we did some local testing and the templates code still works when the site is in "Production" mode (always worth us checking that, because production is 'odd').

• We have a nightly build that returns the actual underling error we get from umbraco here :

https://dev.azure.com/jumoo/Public/_artifacts/feed/nightly/NuGet/uSync/overview/17.3.8-build.20260819.1

If you can test with this version, then you should get the underling reason the template creation is failing.

---

Just a note about production mode:

• the templates are never really on disk, they are expected to be compiled razor views as part of the solution when you perform the dotnet publish.
• uSync is then only adding the DB element of the template, and not touching the files.
• except the umbraco create does actually create a file, which isn't what should happen,
• but then uSync deletes it so the compiled one wins again.

So i suppose file permissions could cause the issue, as well as some compiled views clashing with templates.

Also we had an issue with Umbraco umbraco/Umbraco-CMS#21600 (comment)
which i think broke this for Umbraco v17.3.0 it was fixed in Umbraco v17.3.2

[KevinJump]

v17.3.8 has been released - and this will surface the actual error (if its still present) from within Umbraco, so if you want to try and see if that sheds any light on this.

[gohil-chetan]

Thanks, @KevinJump , for letting me know.

I will check it from my end and get back to you.