Today we updated our application the latest angular version (prior, it was generally 16.1.0, now its 16.2.12). Also of the infragistics packages we updated igniteui-angular-i18n from 15.1.21 to 15.1.34.

On ng serve there is now a new error message with the content: 

Module build failed (from ./node_modules/sass_loader/dist/cjs.js) with the error mentioned in the title, and with an Undefined variable.
It happens on the line of:
@include theme($color-palette, $roundness: 0.25)

It worked previously, but the update broke it. Is there any solution to this issue?

The stacktrace points to the issue, that the $theme variable (for example in _rating-theme.scss) is now undefined. The $theme undefined appears in other components from infragistics as well now.