Backoffice/admin CSS Smidge/NUglify error, breaking package styling

Questions
1

When Umbraco admin/backoffice loads, it loads this CSS:

/sb/umbraco-backoffice-css.css.v637823303400000000

However, this URL returns a 500 because of the following error:

System.InvalidOperationException: Expected expression, found ‘’,Expected expression, found ‘’
at Smidge.Nuglify.NuglifyCss.ProcessAsync(…)
…
at Smidge.FileProcessors.CssImportProcessor.ProcessAsync

In the development environment Smidge/NUglify doesn’t seem to run, so we get one CSS for each package, and of all these work.

So it seems the backoffice/admin Smidge/NUglify is broken because something in the installation, or a package, makes Smidge/NUglify try to import an empty file, or something similar.

Clearing the App_Plugins folder and re-installing and re-deploying all packages does not help.

As a workaround, is there a way to turn off backoffice/admin Smidge/NUglify to get the same behavior as in development? Removing the RuntimeMinification block from AppSettings doesn’t seem to make a difference.

Any other ideas what could be breaking this?

The packages that load CSS files are:

  • Diplo GodMode
  • Translation Manager
  • Translation Manager Languagewire Connector
  • Umbraco Forms
  • uSync

Removing each package one by one and testing is a bit tedious because it works in development. And when clearing the App_Plugins folder in production Umbraco still tries to load CSS/JS from those folders, so Smidge/NUglify breaks anyway. Not sure how Umbraco “remembers” what to load.

EDIT: SimpleRedirects is missing from the package list above, and it seems to be causing the problem (see below).

This is a companion discussion topic for the original entry at https://our.umbraco.com/forum/108469-backofficeadmin-css-smidgenuglify-error-breaking-package-styling
2

Throwing my experience in here because I’ve had this issue in v13.8.0 today:

This post originated from a post on the old forums, which provides more detail: backofficeadmin css smidgenuglify error breaking package styling

Another post from the old discord chats is here: Smidge fails to find files Umbraco #help-with-umbraco

Another one for good luck: Missing Backoffice CSS Files for Forms - v13.8.0 and Forms v13.4.1 - #9 by BradleyCSO

(I can’t reply to any of the above posts, so hopefully any searcher finds this)

The long and short of this is: one of the App_Plugins css is failing due to it being invalid. In my case, I had added a plugin myself for a custom field, where the css file was literally

body {
}

And that broke smidge. Once I removed the reference to that file in my package.manifest, it worked fine.

I was able to test this faster by Sebastiaan’s suggestion of publishing to disk and running
dotnet MyProject.dll --urls "https://*:5001" , which saved me publishing everything to check.

I hope this helps someone.

4

Another possibly undocumented feature, is that if you add a *.min.(js|css) into the smidge bundle, smidge knows not to try and nuglify it, so simply includes in the bundle without trying to minify/compress so if your css was causing nuglify issues it now won’t. (though you should probably find out what’s causing the failure)

5

Yes, for usync we use the Bundle option in the package. Manifest, by setting this to none, it doesn’t get bundled up and hence isn’t reliant on the single css/js file in production actually working.

as long as you a) don’t care about minification or b) do the minification yourself, this means your bundle can avoid going through smidge.