For one of my projects I have a longstanding issue with either one or both virtual controllers not being able to startup. If I close and restart the solution multiple times it eventually works (both controllers manage to startup).
- Happy to provide the backup of both robots that are causing this issue.
- I’ve tried creating a new project and when adding a new VC from backup the same errors occur.
- RobotStudio 2025.3 (64-bit) - Version 25.3.11371.0
- Edition Windows 11 Pro
Version 25H2
Installed on 18/03/2025
OS build 26200.7840
Experience Windows Feature Experience Pack 1000.26100.291.0
The errors I receive are the following:
04/03/2026 11:58:56
RobotStudio .NET exception: C0040403 : No response from controller.
Netscan timeout
============================================
Base exception: RobApiException
C0040403 : No response from controller.
Netscan timeout
at RobotStudio.Services.RobApi.RobVcFactory.<>c__DisplayClass7_0.<<StartVC>b__0>d.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at RobotStudio.Services.RobApi.RobVcFactory.<StartVC>d__7.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at RobotStudio.Services.Systems.SystemHelper.<RestoreBackup>d__6.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at RobotStudio.Services.Systems.SystemHelper.<RestoreBackup>d__6.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at RobotStudio.Services.Systems.VcProjectHelper.<RecreateOrRestoreProjectControllerIfNeeded>d__11.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at ABBInternal.Controller.StationVirtualControllerManager.<StartLoadedController>d__23.MoveNext()
04/03/2026 12:00:34
RobotStudio .NET exception: The RPC server is unavailable. (Exception from HRESULT: 0x800706BA)
============================================
Base exception: COMException
The RPC server is unavailable. (Exception from HRESULT: 0x800706BA)
at RobotStudio.Services.RobApi.Interop.IRobVC.IsRunning(Int32& bRunning)
at RobotStudio.Services.RobApi.RobVcFactory.<WaitUntilServerRunning>d__10.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at RobotStudio.Services.RobApi.RobVcFactory.<>c__DisplayClass7_0.<<StartVC>b__0>d.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at RobotStudio.Services.RobApi.RobVcFactory.<StartVC>d__7.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at RobotStudio.Services.Controller.ControllerService.<StartAndWaitForConnectionAsync>d__34.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at RobotStudio.Services.Controller.ControllerService.<StartAsync>d__32.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at RobotStudio.Services.Controller.ControllerService.<Start>d__31.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at ABBInternal.Controller.StationVirtualControllerManager.<StartLoadedController>d__23.MoveNext()
.rslog
----HEADER BEGIN----
MachineId=fec2b26b-f526-40c6-b202-c59367cc95bb
OSIdentifier=Microsoft Windows NT 10.0.26200.0
OSVersion=10.0.26200.0
OSLanguage=en-US|English (United States)
OSBitness=64
CLRVersion=4.0.30319.42000
Locale=en-CH|English (Switzerland)
ProcessorCoreCount=12
ProcessorLogicalCount=20
ProcessorNames=12th Gen Intel(R) Core(TM) i7-12700KF
PhysicalMemory=34164047872
GfxCardNames=NVIDIA GeForce RTX 4070
GfxDriverDates=20251230
GfxDriverVersions=32.0.15.9174
NumDisplays=2
PrimaryDisplayResolution=2560x1440
Domain=<local>
ComputerManufacturer=ASUS
ComputerModel=System Product Name
PCSystemType=1
SessionId=ae739292-cc80-4d17-b23d-1ec959162f43
SessionStart=03/04/2026 11:54:10
SessionStartUtc=03/04/2026 10:54:10
AppVersion=25.3.11371.0
BuildTag=Production
AppBitness=64
AppLanguage=en-US|English (United States)
InstallDir=C:\Program Files (x86)\ABB\RobotStudio 2025
Licenses=
LicenseFeatures=
LicenseLevel=Trial
PremiumLicenseType=Standalone
MinimalInstall=False
BackstageStartPage=BackstageTabNew
ColorTheme=Silver
----HEADER END----
----LOG BEGIN----
00:00:00|UIThreadWatchdog|Started
00:00:03.0019683|UIThreadWatchdog|Warning|2000 ms delay on UI thread
00:00:03.0204119|AddinAdded|I/O Engineering|General
00:00:03.1050900|AddinAdded|Visual SafeMove 2|General
00:00:03.3370187|AddinAdded|Equipment Builder|General
00:00:03.4104877|AddinAdded|Point Cloud Import|General
00:00:05.0024846|UIThreadWatchdog|Warning|4000 ms delay on UI thread
00:00:07.0031741|UIThreadWatchdog|Warning|6000 ms delay on UI thread
00:00:08.5309345|UserLogMessage|Warning||RobotStudio license will expire in 7 days
00:00:09.5309246|User|SignedIn
00:00:31.5869890|UIThreadWatchdog|Warning|2000 ms delay on UI thread
00:00:31.5992801|AddinLoading|I/O Engineering
00:00:31.6030024|AddinLoaded|I/O Engineering
00:00:31.6030024|AddinLoading|Visual SafeMove 2
00:00:32.7492813|AddinLoaded|Visual SafeMove 2
00:00:32.8952906|GraphicsFeatureLevel|D3D_FEATURE_LEVEL_11_0
00:00:33.5879220|UIThreadWatchdog|Warning|4000 ms delay on UI thread
00:00:35.5883742|UIThreadWatchdog|Warning|6000 ms delay on UI thread
00:00:35.7830204|AddinLoading|Equipment Builder
00:00:35.7998422|AddinLoaded|Equipment Builder
00:00:35.7998422|AddinLoading|Point Cloud Import
00:00:35.8081374|AddinLoaded|Point Cloud Import
00:01:12.5098335|BackstageVisibilityChanged|False
00:01:15.1943852|UIThreadWatchdog|Warning|2000 ms delay on UI thread
00:01:16.2880801|StationCreated
00:01:16.5778409|ActiveWindowChanged|GraphicWindow|NoId
00:02:08.4024812|ExecutingCommand|ControllerAddTemplate|Activated
00:02:44.0918221|VCAffinity|2
00:02:56.8239726|ControllerConnectionState|{FA797569-1650-4410-B717-7C2A02344B08}|0
00:03:04.9652566|ControllerConnectionState|{FA797569-1650-4410-B717-7C2A02344B08}|1
00:03:04.9805310|UserLogMessage|Error|EventLog|6700-138391: 90802 - Lock Information Error
00:03:04.9805310|UserLogMessage|Error|EventLog|6700-138391: 90531 - Cyclic Brake Check needs to be done
00:03:10.0302673|ControllerConnectionState|{FA797569-1650-4410-B717-7C2A02344B08}|0
00:03:10.6429900|StartingVC|1
00:03:10.7164562|VCAffinity|2
00:03:13.3344254|Exception|899ebaf1-a3e4-4c5a-9022-09a362d18384|System.Runtime.InteropServices.COMException|UserVisible
----EXCEPTION BEGIN----
The RPC server is unavailable. (Exception from HRESULT: 0x800706BA)
at RobotStudio.Services.RobApi.Interop.IRobVC.IsRunning(Int32& bRunning)
at RobotStudio.Services.RobApi.RobVcFactory.<WaitUntilServerRunning>d__10.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at RobotStudio.Services.RobApi.RobVcFactory.<>c__DisplayClass7_0.<<StartVC>b__0>d.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at RobotStudio.Services.RobApi.RobVcFactory.<StartVC>d__7.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at RobotStudio.Services.Controller.ControllerService.<StartAndWaitForConnectionAsync>d__34.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at RobotStudio.Services.Controller.ControllerService.<StartAsync>d__32.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at RobotStudio.Services.Controller.ControllerService.<Start>d__31.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at ABBInternal.Controller.StationVirtualControllerManager.<StartNewController>d__26.MoveNext()
----EXCEPTION END----