[IntelliJ] Uncaught Exception Operator called default onErrorDropped reactor.core.Exceptions$ErrorCallbackNotImplemented: java.util.concurrent.TimeoutException: Did not observe any item or terminal signal within 10000ms in 'subscribeOnCallable' (and no fal

IntelliJ build version: 2026.1.4 IU-261.26222.65
OS: Windows 11
JDK: JetBrains s.r.o. 25.0.3
Plugin version: 3.97.6-2026.1
Additional Info: None
Parent component:

com.intellij.openapi.wm.impl.IdeRootPane[,7,7,1536x816,layout=com.intellij.openapi.wm.impl.IdeRootPane$CustomHeaderRootLayout,alignmentX=0.0,alignmentY=0.0,border=,flags=449,maximumSize=,minimumSize=,preferredSize=]

Error message:

IdeaLoggingEvent[message=Operator called default onErrorDropped, throwable=reactor.core.Exceptions$ErrorCallbackNotImplemented: java.util.concurrent.TimeoutException: Did not observe any item or terminal signal within 10000ms in 'subscribeOnCallable' (and no fallback has been configured)
Caused by: java.util.concurrent.TimeoutException: Did not observe any item or terminal signal within 10000ms in 'subscribeOnCallable' (and no fallback has been configured)

The report names an IntelliJ plugin version, Windows 11, JDK 25.0.3, and a Reactor timeout in subscribeOnCallable, but no source file, test, or entry point. Start by reproducing the uncaught exception with these versions and trace the timeout's originating operation; done means the cause is identified and the exception no longer reaches IntelliJ as an uncaught error.