Lumo theme problems after migrating to 3.0

chrisbeaham · September 29, 2026, 7:08pm

Jmix version: 3.0.2
Jmix Studio plugin version: 3.0.3-262
IntelliJ IDEA 2026.2.3
Build #IU-262.10968.63, built on September 16, 2026
Source revision: 1dfe5ce6ce2e9
Runtime version: 25.0.4+1-b508.27 x86_64
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Toolkit: sun.lwawt.macosx.LWCToolkit
Operating System: macOS 26.7 (25G229)
Exception reporter ID: 130125217606a47-a271-49c2-abca-7694492439bf
JCEF version: 144.0.15-262-b37
GC: G1 Young Generation, G1 Concurrent GC, G1 Old Generation
Metal Rendering is ON
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Browser: Safari - Version 27.0 (21625.1.29.18.28)

Hello Everyone

I have two issues, one of which I cannot solve.

Issue #1

According to the Release 3.0 documentation Release 3.0 :: Jmix Documentation

“Removes lumoImports from theme.json.” should be done automatically during the migration; here is my theme.json after the migration:

{
“parent”: “jmix-lumo”,
“lumoImports”: [
“typography”,
“color”,
“spacing”,
“badge”,
“utility”
]
}

It was not removed. This is not a problem; I removed it manually in the meantime; however, please check the migration code regarding this. Thank you.

Issue #2

According to the Vaadin documentation https://vaadin.com/docs/latest/upgrad the @Theme annotation is deprecated and should be replaced by @StyleSheet(Lumo.STYLESHEET).

During the 3.0 migration the @StyleSheet(Lumo.UTILITY_STYLESHEET) annotation was automatically added to my application class, as described here Release 3.0 :: Jmix Documentation but when I replace @Theme with @StyleSheet(Lumo.STYLESHEET) my Lumo attributes are not loaded.

@Push
@StyleSheet(Lumo.STYLESHEET)
@StyleSheet(Lumo.UTILITY_STYLESHEET)
@PWA(name = “Notefall”, shortName = “Notefall”, offline @SpringBootApplicationf@EnableConfigurationPropertieslse)
@SpringBootApplication
@EnableConfigurationProperties(ConfigProperties.class)
public class NotefallApplication implements AppShellConfigurator {

I have also tried using only @StyleSheet(Lumo.UTILITY_STYLESHEET) and only @StyleSheet(Lumo.STYLESHEET); none of the combinations work correctly. I do not have any warnings or errors in my console indicating a problem; my interface is simply not displayed/rendered correctly.

Does anyone have any advice regarding this?

Thank you in advance for your support and feedback.

Best regards
Chris

gorelov · September 30, 2026, 7:19am

Hi,

The same Vaadin doc also mentions that the @StyleSheet annotation is to be used for loading one or more stylesheets from public static resources locations (e.g. META-INF/resources/), which means that simply replacing @Theme with @StyleSheet is not enough.

If you create a new project on Jmix 3.0+ you’ll the following:

jmix-lumo and a project theme are imported explicitly

@StyleSheet(Lumo.STYLESHEET)
@StyleSheet(JmixLumo.STYLESHEET)
@StyleSheet("themes/sandbox-31s-lumo/styles.css")
// @StyleSheet(Lumo.UTILITY_STYLESHEET) - should be added manually if you plan to use lumo utility classes or during migration

theme files are located in the META-INF/resources/

Regards,
Gleb