System.ArgumentNullException: Value cannot be null. (Parameter ‘workflowFile’)
at UiPath.Models.WorkflowFileInfo..ctor(String workflowFile)
at UiPath.Executor.Debugger.Client.Models.JobModelSlim.AsJobModel()
at UiPath.Executor.Debugger.Client.Models.ExecutionStartOptionsSlim.GetRunJobArgs()
at UiPath.Executor.Debugger.Client.Services.RobotExecutorProxy.SetupAsync(ExecutionStartOptionsSlim startOptions)
at UiPath.Executor.Debugger.Client.Services.RobotExecutorProxy.StartJobAsync(ExecutionStartOptionsSlim startOptions)
This error occurs when the workflow file path passed to the Robot Executor is null or invalid. Please verify that the Main.xaml file exists in the project folder and the entry point is correctly defined in the project.json. Re-publish the package to Orchestrator to refresh the workflow reference and resolve the issue.
@lr101 Verify all required input arguments and especially those related to the main workflow file are provided.
So i created a blank process with nothing but a log message in the work flow and i am still getting the same issue,
Hello @lr101
Could you please check if the pre-requisites and other recommendations from the documentation are in place?
Hi, @lr101
Make sure Main.xaml exists in your project folder and is properly referenced in project.json. Then, close UiPath Studio delete project.json reopen your project to auto-generate it and restart the Remote Debugging Agent.
How do i check if the remote robot is the same version? if not how do i update it?
On your remote machine, open UiPath Assistant and check the version… it must match the Studio version on your dev machine. If not, just download the same UiPath installer used on your Studio PC and update the robot on the remote machine. restart when done for the update to take effect .
So for my
studio : 2025.0.175 STS
Assistant: 2024.10.8
Your Studio and Assistant versions do not match…so try to
Download and install UiPath Assistant version 2025.0.175 (same as your Studio)
Where can i download from?
Two of the people here seem to just be copying out stuff from Chat GPT, so please be cautious, and I’d recommend against the advice of deleting your project.json. Its bad advice and clearly won’t work if this happens in a totally fresh project.
They aren’t reading the actual issue.
I assume you can run a debug normally, without the remote stuff right?
So if you are struggling only on the remote debugging, what kind of connection are you specifying? Is the robot version matching and are both machines the same platform type (windows / Linux) etc.
Edit: ah I see, you have a mismatch in Studio and robot.
You need to match them, you are on the STS release. You need the LTS release.
Go to
https://cloud.uipath.com/{org_name}/portal_/resource-center to download the different versions (replace org_name with your own)
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i think the issue is the versions of studio and the assistant are different.
My machine versions
Studio: 2025.0.175
Assistant: 2025.0.175
Virtual machine versions
Assistant: 2024.10.8
I agree, I’d edited my answer when I saw, can you try to go the the resource center and install a matching version?
@lr101
You can Download UiPath Studio and Assistant 2025.0.175 STS directly from the official UiPath site (Download UiPath Studio - Automation Tools in your Enterprise | UiPath) or your Automation Cloud Resource Center.
Make sure you grab the installer for your exact version to keep Studio and Assistant in sync
i have access to the reource center and i will download and update to LTS versions
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Hi, @Jon_Smith
really appreciate you highlighting why deleting project.json isn’t a reliable fix especially with a fresh project. Learning from your experience and feedback.
Thanks!
Appreciate you paying attention to that then.
The reason its bad advice is the following:
- It removes any test cases in the project, reverting them to normal workflows.
- It removes any templates in the project
- It removes the dependencies, reverting them to defaults and possibly breaking activities and workflows
- It removes the project compatibility and version, potentially switching it from C# to VB or Cross Platform to Windows
- It removes the entry point(s) and replaces them with default
- It removes various project settings such as the automation being foreground / background or if it requires user interaction
- It removes the project name
In my opinion this is never worth doing. It was bad advice from people who didnt really know how to fix problems and has persisted as a bad equivalent of ‘turn your computer and off again’ but its far far worse.
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Thanks so much for breaking it down with real examples..it seriously helps to see what goes wrong behind the scenes. Your explanation made it crystal clear why deleting project.json can mess up a lot more than I realized. I’ll definitely keep this in mind and avoid recommending risky shortcuts like that. Really appreciate you taking the time to share detailed reasoning behind it.
learning a lot from this!
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