JetBrains plugin fails to load in 2026.2 IDEs with NoClassDefFoundError: com/intellij/ui/jcef/JBCefApp

Before submitting your bug report

• I've tried finding an answer on the Continue docs site
• I'm not able to find an open issue that reports the same bug
• I've seen the troubleshooting guide on the Continue Docs

Relevant environment info

• OS: macOS 15.6 (arm64)
• Continue version: 1.0.67
• IDE version: Rider 2026.2 (build 262.9437.287)

Description

Starting with the 2026.2 platform release, JetBrains ships JCEF (the JetBrains Chromium Embedded Framework, which the Continue tool window renders in) as a separate bundled plugin instead of a part of the core IDE. The new plugin's id is com.intellij.modules.jcef, which up to 2026.1 was a module alias of the core IDE itself. A plugin that uses JCEF classes now has to declare an explicit dependency on it in plugin.xml; without one, the plugin's classloader can no longer resolve them.

The Continue plugin doesn't declare that dependency, so on any 2026.2 IDE it crashes during initialization with java.lang.NoClassDefFoundError: com/intellij/ui/jcef/JBCefApp and the tool window never loads.

Other JCEF-based plugins hit the same wall. The AsciiDoc plugin, for example, fixed it with a single line in plugin.xml (see asciidoctor/asciidoctor-intellij-plugin#2073 and the corresponding PR #2081):

<depends>com.intellij.modules.jcef</depends>

I verified that the same line fixes Continue: after patching it into the descriptor of the installed plugin jar, the plugin initializes and the tool window loads normally in Rider 2026.2. Since the id was a core module alias before 2026.2, the added dependency is backwards compatible with the older IDE versions the plugin supports.

I'll open a PR with the fix.

To reproduce

1. Install Continue 1.0.67 in any JetBrains 2026.2 IDE (I used Rider 2026.2).
2. Open the Continue tool window.
3. The panel never loads and the error below appears in the IDE log.

Log output

com.intellij.openapi.diagnostic.UnhandledException: com/intellij/ui/jcef/JBCefApp
    at com.intellij.openapi.application.impl.ExceptionsKt.processUnhandledException(exceptions.kt:56)
    ...
Caused by: java.lang.NoClassDefFoundError: com/intellij/ui/jcef/JBCefApp
    at com.github.continuedev.continueintellijextension.browser.ContinueBrowserService.load(ContinueBrowserService.kt:29)
    at com.github.continuedev.continueintellijextension.browser.ContinueBrowserService.<init>(ContinueBrowserService.kt:17)
    ...
    at com.github.continuedev.continueintellijextension.browser.ContinueBrowserService$Companion.getBrowser(ContinueBrowserService.kt:71)
    at com.github.continuedev.continueintellijextension.continue.CoreMessenger.handleMessage(CoreMessenger.kt:61)
    at com.github.continuedev.continueintellijextension.continue.process.ContinueProcessHandler$1.invokeSuspend(ContinueProcessHandler.kt:33)
    ...
Caused by: java.lang.ClassNotFoundException: com.intellij.ui.jcef.JBCefApp PluginClassLoader(plugin=PluginMainDescriptor(name=Continue, id=com.github.continuedev.continueintellijextension, version=1.0.67, isBundled=false), packagePrefix=null, state=active, parents=...)
    at com.intellij.ide.plugins.cl.PluginClassLoader.loadClass(PluginClassLoader.kt:154)
    at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:490)

Find the JetBrains plugin.xml descriptor and inspect its existing dependency declarations. Verify the JCEF dependency requirement against the 2026.2 IDE behavior, then test the plugin in a 2026.2 IDE and an older supported IDE; done means the Continue tool window loads without the JBCefApp error in both.