Missing Method Exception with running Servo Pad Skill in ARC

Question

, could you please provide insights into the following exception encountered when running the ARC servo Pad Skill?

Background:

ARC Version: 2025.01.30.00
Operating System: Windows 11
Robot: Humanoid Meccano Meccanoid
Modifications: Original servos have been replaced with EZ-Robot servos.
Note: The setup functioned correctly with previous updates of ARC.

Exception Details:

System.MissingMethodException: Method not found: 'Jint.Engine ARC.Scripting.JavaScript.JavascriptEngine.get_JintEngine()'.
   at Servo_Script.ServoBindManager.Servo_OnServoMoveDetailed2(EZB ezb, ServoPositionItem[] servos, ServoPositionItem[] servosAfterFineTuned)
   at EZ_B.Servo.iW9mg2DKj8ZZfHLnnkdr(Object , Object , Object , Object )
   at EZ_B.Servo.SetServoPosition(ServoPositionItem[] servos)
   at ARC.EZBManager.SetServoPositionScalar(ServoDescriptor[] servos, Single inputMin, Single inputMax, Single input)
   at ARC.EZBManager.L8rQ7iJ6lxLkgMJojgqE(Object , Single inputMin, Single inputMax, Single input)
   at ARC.EZBManager.SetServoPositionScalar(ServoDescriptor[] servos, Int32 inputMin, Int32 inputMax, Int32 input)
   at ARC.UCForms.FormServoPad.vySlvXgqpJY(Object  , MouseEventArgs  )
   at System.Windows.Forms.Control.OnMouseMove(MouseEventArgs e)
   at System.Windows.Forms.Control.WmMouseMove(Message& m)
   at System.Windows.Forms.Control.WndProc(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
   at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)

I would appreciate any guidance on resolving this issue. Thank you!

DJ Sures · Answer

That's not from the servo pad skill. what other skills do you have? it's from something else.

Synthiam Support · Answer

DJ is correct - that error originates from a different robot skill. Can you list what other skills are being used?

Athena · Answer

It seems like the exception you're encountering is not directly related to the Servo Pad Skill but might be coming from another robot skill in your project. To help you resolve this issue, could you please provide a list of all the robot skills you have added to your ARC project? This will help us identify which skill might be causing the exception. Additionally, here are a few steps you can take to troubleshoot the issue: 1. Update ARC: Ensure you are using the latest version of ARC. Sometimes, updating to the latest version can resolve compatibility issues. 2. Check Skill Dependencies: Some robot skills might have dependencies on other skills or specific versions of ARC. Make sure all your skills are compatible with the version of ARC you are using. 3. Review Skill Configuration: Double-check the configuration of each skill to ensure they are set up correctly, especially after replacing the servos. 4. Isolate the Issue: Try disabling or removing skills one by one to see if the exception persists. This can help identify which skill is causing the problem. 5. Reinstall Skills: If you identify a specific skill causing the issue, try removing and reinstalling it. Once you provide more information about the skills in your project, I can offer more targeted assistance.

wakeuplearn · Answer

Thank you for the quick response. I had a lot of skills installed in that project, so created a separate test project to help isolate the issue. This new project has the Connection Skill, EZB v4 Info Skill, HBridge , PWM, HBridge , SetDigital , and Servo Pad But the error still happens when I click the ServoPad skill to move a servo. The HBridge and other skills seem to work fine.  Also, This configuration is also running on Parallels on my MacBook (which may be a contributor), since my Rock Pi configuration was running a little slow.  The RockPi configuration didn't have this error , but I will double check the ARC version  Thank you for your help.  Here is the error message: Version: 2025.01.30.00 System.MissingMethodException: Method not found: 'Jint.Engine ARC.Scripting.JavaScript.JavascriptEngine.get_JintEngine()'. at Servo_Script.ServoBindManager.Servo_OnServoMoveDetailed2(EZB ezb, ServoPositionItem[] servos, ServoPositionItem[] servosAfterFineTuned) at EZ_B.Servo.iW9mg2DKj8ZZfHLnnkdr(Object , Object , Object , Object ) at EZ_B.Servo.SetServoPosition(ServoPositionItem[] servos) at ARC.EZBManager.SetServoPositionScalar(ServoDescriptor[] servos, Single inputMin, Single inputMax, Single input) at ARC.EZBManager.L8rQ7iJ6lxLkgMJojgqE(Object , Single inputMin, Single inputMax, Single input) at ARC.EZBManager.SetServoPositionScalar(ServoDescriptor[] servos, Int32 inputMin, Int32 inputMax, Int32 input) at ARC.UCForms.FormServoPad.vySlvXgqpJY(Object , MouseEventArgs ) at System.Windows.Forms.Control.OnMouseMove(MouseEventArgs e) at System.Windows.Forms.Control.WmMouseMove(Message& m) at System.Windows.Forms.Control.WndProc(Message& m) at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m) at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m) at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam) ARC.UCForms.FormServoPad.vySlvXgqpJY(Object , MouseEventArgs )

Synthiam Support · Answer

Can you verify that these are the absolute only robot skills in your project that raise that error? - Connection Skill - EZB v4 Info Skill - HBridge - PWM - HBridge  - SetDigital  - Servo Pad None of these robot skills can raise that error. Please revisit your robot skill project and provide a list of robot skills. You can share the robot project by posting it here (Choose FILE and upload it to the editor) or by saving it to the public cloud and letting us know the name. *Note: We edited your previous message to format the error correctly in a [ code ] quote.

wakeuplearn · Answer

Hello,  Here is the screen shot of the ServoPad project on Parallels with ARC 2025.01.30.00.  The version 2025 01.15.00 does not generate this error on my RockPi configuration.

Synthiam Support · Answer

Thank you for posting the image. However, the thumbnail shows there may have been other robot skills in the project. Can you please let us know what robot skills were in the project so we can identify a solution for you?

wakeuplearn · Answer

Hi @Athena,  Is there a way to rollback to a previous version of ARC? Thank you for your help.

Synthiam Support · Answer

Athena does not have access to provide files to download - she is an AI, not a person. I am a human working to assist you this Saturday afternoon. Please let me know what robot skills you used in this project, and I will help you. If you have an existing project that you were using, let me know what robot skills were in the project before they were removed. I believe a robot's skills are somehow resident and causing the error. A robot skill binding to the on-servo movement event, as seen in the error. I can help fix this error if you tell me what robot skills were used in this project or this ARC session.

wakeuplearn · Answer

Thank you.. The skills used were ServoPad,  EZ-B v4 info,  and Connection.  ARC is also running in a Parallels Virtual machine running Windows 11 which could be causing the problem.   I would like to try my configuration on a previous version of ARC (2025 1.15.00) if possible.

Synthiam Support · Answer

Reviewing the log and comparing against robot skills using the servo binding class. Would you have used the Servo Script robot skill?

DJ Sures · Answer

Oh good call support, you nailed it. It was right there in front of us this whole time. System.MissingMethodException: Method not found: 'Jint.Engine ARC.Scripting.JavaScript.JavascriptEngine.get_JintEngine()'. at Servo_Script.ServoBindManager.Servo_OnServoMoveDetailed2(EZB ezb, ServoPositionItem[] servos, ServoPositionItem[] servosAfterFineTuned) The servo script is creating that error. Looks like there's two issues.  1) servo script isn't disposting itself correctly by not releasing events it has assigned to itself 2) the updated arc javascript engine update isn't exposed to the robot skill

Synthiam Support · Answer

Okay an update has been posted for that fix. It was in front of me the whole time - I can't believe I missed it. The update is documented in the previous release: https://synthiam.com/Products/ARC/Releases/ARC-2025-02-01-00-Pro-and-Runtime-22624 In the future, we'll need to identify better what robot skills were used in a project to locate causes quicker. Perhaps a log to the debug when robot skills are added to a project. That way, we can look through a history and identify the cause of an issue.

Synthiam Support · Answer

I have also updated the Servo Script and the version update has been documented: https://synthiam.com/Support/Skills/Scripting/Servo-Script?id=19068

DJ Sures · Answer

Awesome - all is working. The updated ARC release gives the servo script access to the new Javascript engine, and the servo script robot skill has been updated to unsubscribe from events by properly disposing itself.