[plugin] Error: Unknown actor WorkspaceMain

[kittaakos]

I got these when I was verifying #5279.

Steps:

• Follow the steps from here. (In a nutshell, start a Java debug process with VS Code extensions)
• Refresh your electron browser window.

root WARN Plugin contributes items to a menu with invalid identifier: debug/toolBar
root INFO Started watching the git repository: file:///c%3A/Users/kittaakos/dev/maven-demo
root INFO Config file tasks.json does not exist under file:///c%3A/Users/kittaakos/dev/maven-demo
root INFO [nsfw-watcher: 960] Started watching: c:\Users\kittaakos\dev\maven-demo\.theia\launch.json
root INFO [hosted-plugin: 13388] PLUGIN_HOST(13388): PluginManagerExtImpl/init()
root INFO [hosted-plugin: 13388] PLUGIN_HOST(13388): initializing(java@0.47.0 with C:\Users\kittaakos\dev\theia\packages
\plugin-ext-vscode\lib\node/plugin-vscode-init.js)
PLUGIN_HOST(13388): initializing(vscode-java-debug@0.20.0 with C:\Users\kittaakos\dev\theia\packages\plugin-ext-vscode\l
ib\node/plugin-vscode-init.js)
root INFO [hosted-plugin: 13388] Debugger contribution has been registered: java
root INFO [hosted-plugin: 13388] PLUGIN_HOST(13388): PluginManagerExtImpl/loadPlugin(C:\Users\KITTAA~1\AppData\Local\Tem
p\vscode-unpacked\redhat.java-0.47.0.vsix\extension\dist\extension)
root INFO [nsfw-watcher: 960] Started watching: c:\Users\kittaakos\dev\maven-demo\src\test\java\demo\AppTest.java
Started watching: c:\Users\kittaakos\dev\maven-demo\.theia\launch.json
root INFO [nsfw-watcher: 960] Started watching: c:\Users\kittaakos\dev\maven-demo\src\main\java\demo\App.java
root INFO [hosted-plugin: 13388] { message:
   'Starting Java server with: C:\\PROGRA~1\\Java\\JDK18~1.0_1\\bin\\java -Declipse.application=org.eclipse.jdt.ls.core.
id1 -Dosgi.bundles.defaultStartLevel=4 -Declipse.product=org.eclipse.jdt.ls.core.product -Dfile.encoding=UTF-8 -DwatchPa
rentProcess=false -noverify -Xmx1G -XX:+UseG1GC -XX:+UseStringDeduplication -jar C:\\Users\\KITTAA~1\\AppData\\Local\\Te
mp\\vscode-unpacked\\redhat.java-0.47.0.vsix\\extension\\server\\plugins\\org.eclipse.equinox.launcher_1.5.500.v20190715
-1310.jar -configuration C:\\Users\\KITTAA~1\\AppData\\Local\\Temp\\vscode-unpacked\\redhat.java-0.47.0.vsix\\extension\
\server\\config_win -data C:\\Users\\kittaakos\\AppData\\Roaming\\.theia\\workspace-storage\\fa1b2a6a67bcc2e6af7fd211d4a
a4915\\redhat.java\\jdt_ws',
  level: 'info',
  timestamp: '2019-08-02 08:49:43.692' }
root INFO [hosted-plugin: 13388] PLUGIN_HOST(13388): PluginManagerExtImpl/loadPlugin(C:\Users\KITTAA~1\AppData\Local\Tem
p\vscode-unpacked\vscjava.vscode-java-debug-0.20.0.vsix\extension\dist\extension)
root INFO [hosted-plugin: 13388] Debug configuration provider has been registered: java
root INFO [hosted-plugin: 13388] settings: {"maxStringLength":0,"showStaticVariables":false,"showQualifiedNames":false,"
showHex":false,"showLogicalStructure":true,"showToString":true,"logLevel":"WARNING","javaHome":"C:\\PROGRA~1\\Java\\JDK1
8~1.0_1","hotCodeReplace":"manual"}
root INFO Stopped watching the git repository: file:///c%3A/Users/kittaakos/dev/maven-demo
root INFO [nsfw-watcher: 12052] Started watching: c:\Users\kittaakos\.theia
root INFO Using Git [2.22.0.rc3.windows.1] from the PATH. (C:\Program Files\Git\cmd\git.exe)
root INFO [nsfw-watcher: 12052] Started watching: c:\Users\kittaakos\dev\maven-demo
root WARN Collided keybinding is ignored;  {"command":"outlineView:toggle","keybinding":"ctrlcmd+shift+s"}  collided wit
h  {"command":"file.saveAs","keybinding":"ctrl+shift+s"}
root WARN Could not register keybinding:
  {"command":"outlineView:toggle","keybinding":"ctrlcmd+shift+s"}
Error: "ctrlcmd+shift+s" is in collision with something else [scope:0]
root WARN Collided keybinding is ignored;  {"command":"passthrough","keybinding":"ctrl+k","context":"terminalActive"}  c
ollided with  {"command":"terminal:clear","keybinding":"ctrlcmd+k","context":"terminalActive"}
root WARN Could not register keybinding:
  {"command":"passthrough","keybinding":"ctrl+k","context":"terminalActive"}
Error: "ctrl+k" is in collision with something else [scope:0]
root WARN TabBarToolbarRegistry.onStart is slow, took: 168.7000000383705 ms
root WARN ElectronMenuContribution.onStart is slow, took: 159.8000000230968 ms
root WARN LanguagesFrontendContribution.onStart is slow, took: 684.9999999976717 ms
root INFO [nsfw-watcher: 12052] Started watching: c:\Users\kittaakos\dev\maven-demo
root WARN EditorNavigationContribution.onStart is slow, took: 2547.8000000002794 ms
root WARN Couldn't restore widget state for debug-console. Error: TypeError: Cannot read property 'getControl' of undefi
ned
root ERROR [hosted-plugin: 13388] Promise rejection not handled in one second: Error: Unknown actor WorkspaceMain
With stack trace: Error: Unknown actor WorkspaceMain
    at RPCProtocolImpl.doInvokeHandler (C:\Users\kittaakos\dev\theia\packages\plugin-ext\lib\api\rpc-protocol.js:200:19)
    at RPCProtocolImpl.invokeHandler (C:\Users\kittaakos\dev\theia\packages\plugin-ext\lib\api\rpc-protocol.js:192:41)
    at RPCProtocolImpl.receiveRequest (C:\Users\kittaakos\dev\theia\packages\plugin-ext\lib\api\rpc-protocol.js:154:45)
    at RPCProtocolImpl.receiveOneMessage (C:\Users\kittaakos\dev\theia\packages\plugin-ext\lib\api\rpc-protocol.js:123:2
2)
    at C:\Users\kittaakos\dev\theia\packages\plugin-ext\lib\api\rpc-protocol.js:55:89
    at C:\Users\kittaakos\dev\theia\packages\plugin-ext\lib\api\rpc-protocol.js:233:17
    at C:\Users\kittaakos\dev\theia\packages\core\lib\common\event.js:161:33
    at CallbackList.invoke (C:\Users\kittaakos\dev\theia\packages\core\lib\common\event.js:176:39)
    at Emitter.fire (C:\Users\kittaakos\dev\theia\packages\core\lib\common\event.js:264:29)
    at ChildProcess.<anonymous> (C:\Users\kittaakos\dev\theia\packages\plugin-ext\lib\hosted\node\hosted-plugin-process.
js:145:21)
Promise rejection not handled in one second: Error: Unknown actor WorkspaceMain
With stack trace: Error: Unknown actor WorkspaceMain
    at RPCProtocolImpl.doInvokeHandler (C:\Users\kittaakos\dev\theia\packages\plugin-ext\lib\api\rpc-protocol.js:200:19)
    at RPCProtocolImpl.invokeHandler (C:\Users\kittaakos\dev\theia\packages\plugin-ext\lib\api\rpc-protocol.js:192:41)
    at RPCProtocolImpl.receiveRequest (C:\Users\kittaakos\dev\theia\packages\plugin-ext\lib\api\rpc-protocol.js:154:45)
    at RPCProtocolImpl.receiveOneMessage (C:\Users\kittaakos\dev\theia\packages\plugin-ext\lib\api\rpc-protocol.js:123:2
2)
    at C:\Users\kittaakos\dev\theia\packages\plugin-ext\lib\api\rpc-protocol.js:55:89
    at C:\Users\kittaakos\dev\theia\packages\plugin-ext\lib\api\rpc-protocol.js:233:17
    at C:\Users\kittaakos\dev\theia\packages\core\lib\common\event.js:161:33
    at CallbackList.invoke (C:\Users\kittaakos\dev\theia\packages\core\lib\common\event.js:176:39)
    at Emitter.fire (C:\Users\kittaakos\dev\theia\packages\core\lib\common\event.js:264:29)
    at ChildProcess.<anonymous> (C:\Users\kittaakos\dev\theia\packages\plugin-ext\lib\hosted\node\hosted-plugin-process.
js:145:21)
Promise rejection not handled in one second: Error: Unknown actor WorkspaceMain
With stack trace: Error: Unknown actor WorkspaceMain
    at RPCProtocolImpl.doInvokeHandler (C:\Users\kittaakos\dev\theia\packages\plugin-ext\lib\api\rpc-protocol.js:200:19)
    at RPCProtocolImpl.invokeHandler (C:\Users\kittaakos\dev\theia\packages\plugin-ext\lib\api\rpc-protocol.js:192:41)
    at RPCProtocolImpl.receiveRequest (C:\Users\kittaakos\dev\theia\packages\plugin-ext\lib\api\rpc-protocol.js:154:45)
    at RPCProtocolImpl.receiveOneMessage (C:\Users\kittaakos\dev\theia\packages\plugin-ext\lib\api\rpc-protocol.js:123:2
2)
    at C:\Users\kittaakos\dev\theia\packages\plugin-ext\lib\api\rpc-protocol.js:55:89
    at C:\Users\kittaakos\dev\theia\packages\plugin-ext\lib\api\rpc-protocol.js:233:17
    at C:\Users\kittaakos\dev\theia\packages\core\lib\common\event.js:161:33
    at CallbackList.invoke (C:\Users\kittaakos\dev\theia\packages\core\lib\common\event.js:176:39)
    at Emitter.fire (C:\Users\kittaakos\dev\theia\packages\core\lib\common\event.js:264:29)
    at ChildProcess.<anonymous> (C:\Users\kittaakos\dev\theia\packages\plugin-ext\lib\hosted\node\hosted-plugin-process.
js:145:21)
Promise rejection not handled in one second: Error: Unknown actor WorkspaceMain
With stack trace: Error: Unknown actor WorkspaceMain
    at RPCProtocolImpl.doInvokeHandler (C:\Users\kittaakos\dev\theia\packages\plugin-ext\lib\api\rpc-protocol.js:200:19)
    at RPCProtocolImpl.invokeHandler (C:\Users\kittaakos\dev\theia\packages\plugin-ext\lib\api\rpc-protocol.js:192:41)
    at RPCProtocolImpl.receiveRequest (C:\Users\kittaakos\dev\theia\packages\plugin-ext\lib\api\rpc-protocol.js:154:45)
    at RPCProtocolImpl.receiveOneMessage (C:\Users\kittaakos\dev\theia\packages\plugin-ext\lib\api\rpc-protocol.js:123:2
2)
    at C:\Users\kittaakos\dev\theia\packages\plugin-ext\lib\api\rpc-protocol.js:55:89
    at C:\Users\kittaakos\dev\theia\packages\plugin-ext\lib\api\rpc-protocol.js:233:17
    at C:\Users\kittaakos\dev\theia\packages\core\lib\common\event.js:161:33
    at CallbackList.invoke (C:\Users\kittaakos\dev\theia\packages\core\lib\common\event.js:176:39)
    at Emitter.fire (C:\Users\kittaakos\dev\theia\packages\core\lib\common\event.js:264:29)
    at ChildProcess.<anonymous> (C:\Users\kittaakos\dev\theia\packages\plugin-ext\lib\hosted\node\hosted-plugin-process.
js:145:21)
Promise rejection not handled in one second: Error: Unknown actor WorkspaceMain
With stack trace: Error: Unknown actor WorkspaceMain
    at RPCProtocolImpl.doInvokeHandler (C:\Users\kittaakos\dev\theia\packages\plugin-ext\lib\api\rpc-protocol.js:200:19)
    at RPCProtocolImpl.invokeHandler (C:\Users\kittaakos\dev\theia\packages\plugin-ext\lib\api\rpc-protocol.js:192:41)
    at RPCProtocolImpl.receiveRequest (C:\Users\kittaakos\dev\theia\packages\plugin-ext\lib\api\rpc-protocol.js:154:45)
    at RPCProtocolImpl.receiveOneMessage (C:\Users\kittaakos\dev\theia\packages\plugin-ext\lib\api\rpc-protocol.js:123:2
2)
    at C:\Users\kittaakos\dev\theia\packages\plugin-ext\lib\api\rpc-protocol.js:55:89
    at C:\Users\kittaakos\dev\theia\packages\plugin-ext\lib\api\rpc-protocol.js:233:17
    at C:\Users\kittaakos\dev\theia\packages\core\lib\common\event.js:161:33
    at CallbackList.invoke (C:\Users\kittaakos\dev\theia\packages\core\lib\common\event.js:176:39)
    at Emitter.fire (C:\Users\kittaakos\dev\theia\packages\core\lib\common\event.js:264:29)
    at ChildProcess.<anonymous> (C:\Users\kittaakos\dev\theia\packages\plugin-ext\lib\hosted\node\hosted-plugin-process.
js:145:21)
Promise rejection not handled in one second: Error: Unknown actor WorkspaceMain
With stack trace: Error: Unknown actor WorkspaceMain
    at RPCProtocolImpl.doInvokeHandler (C:\Users\kittaakos\dev\theia\packages\plugin-ext\lib\api\rpc-protocol.js:200:19)
    at RPCProtocolImpl.invokeHandler (C:\Users\kittaakos\dev\theia\packages\plugin-ext\lib\api\rpc-protocol.js:192:41)
    at RPCProtocolImpl.receiveRequest (C:\Users\kittaakos\dev\theia\packages\plugin-ext\lib\api\rpc-protocol.js:154:45)
    at RPCProtocolImpl.receiveOneMessage (C:\Users\kittaakos\dev\theia\packages\plugin-ext\lib\api\rpc-protocol.js:123:2
2)
    at C:\Users\kittaakos\dev\theia\packages\plugin-ext\lib\api\rpc-protocol.js:55:89
    at C:\Users\kittaakos\dev\theia\packages\plugin-ext\lib\api\rpc-protocol.js:233:17
    at C:\Users\kittaakos\dev\theia\packages\core\lib\common\event.js:161:33
    at CallbackList.invoke (C:\Users\kittaakos\dev\theia\packages\core\lib\common\event.js:176:39)
    at Emitter.fire (C:\Users\kittaakos\dev\theia\packages\core\lib\common\event.js:264:29)
    at ChildProcess.<anonymous> (C:\Users\kittaakos\dev\theia\packages\plugin-ext\lib\hosted\node\hosted-plugin-process.
js:145:21)