Issue with 2023.4.0: Unable to run code on robot machine: "Could not load file or assembly 'UiPath.System.Activities, Version="

I recently upgraded to UiPath 23.4.0 on my development machine because I saw it was available. I upgraded a project to use the latest packages, one of which is UiPath.System.Activities 23.4.2. The code works fine on my development machine when I am running it in Studio. But when I run the code in my UiPath Assistant from the orchestrator the below issue happens too.

I pushed my project to the remote machine but the project just stops immediately in orchestrator and I get this error:

“Could not load file or assembly ‘UiPath.System.Activities, Version=, Culture=neutral, PublicKeyToken=null’. The system cannot find the file specified.”

To try to fix it, I installed 23.4.0 on my Robot machine, but that still did not fix it. I then tried deleting all of the packages from “C:\Program Files\UiPath\Studio\Packages” but that also did not fix it. I tried reducing the Runtime Rule of the dependencies in the project from Strict to Lowest Applicable Version, which also did not fix it.

I think the 23.4.2 version of system.activities is not on my robot machine, but I don’t know how to check that.

How can I get this working on my Robot machine?


The packages will be downloaded in this location C:\Users<Username>\.nuget\packages

As workaround please go to this location in your dev and copy the required package and then go to your robot machine and paste it there in the same location

And looks like the packages are not being downloaded on robot machine there can be multiple reasons like firewall blocks or package feed not accessible etc


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Hi @Anil_G, thanks for your response.

I actually see that the project does not work when I install the package to my dev PC. It only works when I run it from Studio. Where are those dependencies stored?

Thanks a lot!

Hi @oscar

  1. You can check the Robot logs to see if there are any errors related to the missing package.
    The logs can be found in the following location: %userprofile%\.nuget\packages\uipath\robot.<version>\logs.

  2. Check if the package is installed on the Robot machine. You can do this by navigating to the following directory: %userprofile%\.nuget\packages\uipath.system.activities.

If the package is not there, then it needs to be installed.


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Hi @Nitya1, thanks for your message. There are no Robot logs at the folder path you mentioned. But as previously mentioned, there is an error related to the missing package: “Could not load file or assembly ‘UiPath.System.Activities, Version=, Culture=neutral, PublicKeyToken=null’. The system cannot find the file specified.”

The package is not installed. So how do I go about getting the latest System.Activities package?


Can you check this and try please


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Hey @Anil_G, I deleted the whole .nuget packages folder and it was re-downloaded by UiPath but the issue still persists :frowning:


Is the UiPath robot is of same version ? or is it of a different version?


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Yep, they are both the same version, 23.4.0. I think maybe because I am using the newest version that for some reason UiPath Orchestrator doesn’t have the latest version of the system.activities package? It’s weird.


As per compatibility matrix they should be

Can you open orchestrator and check the packages once

Also just a blind shot…turn off firewall and see if its able to download

If its present in orchestrator you can change extension to .zip and it should be unpacked which you can copy to the .nuget/packages folder


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Thanks again for your continued assistance! I disabled the firewall, deleted the package from my nuget folder to get a new version of the package, and re-installed it via Assistant and it still doesn’t work.

The compatibility is fine.

Where do I go in Orchestrator to see the System.Activities package? I don’t see it anywhere.


Go to orchestrator → tenants → packages → libraries

Search for the pckage name


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Okay. I did that but I do not see the UiPath.System.Activities in there. I only see my published processes / packages. Thank you btw.


Thats an issue…as your orchestrator should be having them…

Okay so can you find nuget.config file from your robot system…

Its generally in C:\Users\<Username>\appdata\Roaming\nuget

If installation folder is different then open there or search in cdrive

Openit in notepad and check the nuget source in it…

And try adding this


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Hi @oscar
Try to upload the package to orchestrator as oppose to have on the local, we have seen similar issues for our robots
following are some of the things which we have tried and it resolved it

  • Uploading the package to orchestrator tenant or orchestrator host which ever is selected by the admin for your feed
  • Try creating a local path to the package if the default does not work .

Ensure that u are running the bot in the same machine in which u have opened it via studio.

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Thanks guys for the responses.

I made a discovery which you might find interesting!

I deleted the latest version of Studio (23.4.0) and installed 22.10.7.

I made no changes to the project and published it again to Orchestrator.

Now the package works just fine, and it runs perfectly on my development PC as well as my Robot PC.

The only thing that changed was my version of UiPath Studio. 23.4.0 does not work when publishing the package. But 22.10.7 does work.

So there is definitely something wrong in Studio 23.4.0.

I think we just have to wait for UiPath Devs to update and fix Studio 23.4.0, but in the meantime I would suggest using the old and stable version of Studio, 22.10.7.



Hi @oscar ,

can you please replicate your setup again and provide us the Diagnostic Tool report?

Thank you,

I’m having the exact same issue, and it started happening after updating both robot and development machine to version 23.4.0. I think I have found the culprit. I compared the .nuspec file for the published nupkg, and in version 23.4.0 I can find the following dependencies listed:

<dependency id="UiPath.System.Runtime.Windows" version="23.4.2" />	
<dependency id="UiPath.UIAutomation.Activities.Runtime" version="23.4.5" />

And in version 22.10.7:

<dependency id="UiPath.System.Activities" version="[23.4.2]" />
<dependency id="UiPath.UIAutomation.Activities" version="[23.4.5]" />

So basically it looks like the proper dependencies were missing from the nupkg published by new version of Studio? I just added the lines from old version of the .nuspec -file to the new version (I didn’t delete the runtime dependencies, idk if those are actually required?) and re-zipped the packaged and renamed back to .nupkg and boom it works. Hopefully a fix is on the way. :slight_smile:

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Wow nice find, @antti.saaristo!! I will forward this off to my UiPath rep so he can share it with the dev team.

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Awesome, thanks!!

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