[IntelliJ][ReportedByUser] Uncaught Exception *** exception class was changed or removed Operator called default onErrorDropped

[leewilson86]

IntelliJ build version: 2023.2.8 IU-232.10335.12
OS: Mac OS X
JDK: JetBrains s.r.o. 17.0.12
Plugin version: 3.85.1-2023.2
Additional Info: None
Parent component:

com.intellij.openapi.wm.impl.IdeRootPane[,0,0,1512x880,invalid,layout=com.intellij.openapi.wm.impl.IdeRootPane$MyRootLayout,alignmentX=0.0,alignmentY=0.0,border=,flags=449,maximumSize=,minimumSize=,preferredSize=]

Error message:

IdeaLoggingEvent[message=*** exception class was changed or removed, throwable=   Operator called default onErrorDropped
   reactor.core.Exceptions$ErrorCallbackNotImplemented: java.lang.NullPointerException: Cannot invoke "java.util.List.add(Object)" because "this._sessions" is null
Caused by: java.lang.NullPointerException: Cannot invoke "java.util.List.add(Object)" because "this._sessions" is null

[wangmingliang-ms]

Duplicate of #7898