Could not load type 'System.Activities.TextExpressionBase`1' from assembly 'UiPath.Workflow, Version=6.0.0.0,

[Stefan_Reutter]

I’m developing with community edition 23.8.0 and publishing a project to an Enterprise robot on a client’s environment side with version 23.4.3. When running in Studio, the workflow looks normal, but when I try to run it on the robot, I get this error:

Could not load type ‘System.Activities.TextExpressionBase`1’ from assembly ‘UiPath.Workflow, Version=6.0.0.0, Culture=neutral, PublicKeyToken=null’.

I have no new packages, everything used to work in Studio version 23.6, apparently a change since then broke backward compatibility. My client only has robot and I’m developing the process as a service. Since this is the only client where we work like this, it’s not economically feasible to switch to enterprise edition.

Any fix or work-around (such as stopping to force-feed new Studio versions down my throat) would be appreciated.

[postwick (Paul Ostwick)]

When you run it on the robot, it has to download the dependencies. They’re not included inside your project when you publish it. They need to make sure their server can access the online feeds.

[Nitya1 (Nitya Tomar)]

Hi @Stefan_Reutter

The error you’re encountering, “Could not load type ‘System.Activities.TextExpressionBase`1’ from assembly 'UiPath.Workflow,” is indeed related to compatibility issues between different versions of UiPath Studio and UiPath Robot. The error message suggests that there is a mismatch in the assembly versions between your development environment (Studio) and the client’s environment (Robot).

To resolve this issue, you have a few options:

1. Update the Robot Version: The ideal solution would be to update the client’s Robot to a version that matches or is compatible with your development version (23.8.0). This will ensure that the package dependencies align, and you won’t encounter compatibility issues.

2. Downgrade Your Development Version: If updating the client’s Robot is not possible, you may need to downgrade your development version of UiPath Studio to match the client’s version (23.4.3). This ensures compatibility but may limit you from using newer features and improvements in the newer Studio versions.

3. Package Version Management: Check the package versions in your project. Ensure that the packages you are using are compatible with both Studio 23.8.0 and Robot 23.4.3. You might need to downgrade some package versions to match the Robot’s environment.

In general, it’s best to keep both the Studio and Robot versions in sync to avoid compatibility problems. Upgrading or downgrading either component to match the other is usually the most straightforward solution.

[Anil_G (Anil Gorthi)]

@Stefan_Reutter

it is not advised to develop on higher version and deploy on lower

but one workaround you can try is to degrade all your activity packages to lower than 23.4.3 or equal so that the activities are compatible are not forward than the robot version(system and ui specifically)

cheers

[Stefan_Reutter]

Thanks, but this is a cloud Orchestrator and robot also has access to the online feed, I verified this by installing some 23.8 preview packages. The packages of my workflow are all still on 23.4 versions. I’m positive it’s not a package issue, Studio seems to sneak in some additional dependencies during compilation

[Stefan_Reutter]

Thanks for your suggestions, unfortunately none of them are an option for me . As I mentioned in the OP, the customer is on enterprise while I am working with CE to develop a project for them. Updating the robot version to a CE is not possible. Similarly, downgrading Studio is not possible in CE, unless you know something I don’t?

The packages are already on 23.4 versions.

[postwick (Paul Ostwick)]

It’s not sneaking in additional dependencies. There are always many sub dependencies. Go to your project tab and expand one of the dependencies.

What version of Robot is the customer’s server on? If they’re on too old a version, certain package versions won’t work.

[Stefan_Reutter]

It must be doing something weird to the project, maybe not sneaking in dependencies exactly, perhaps the dependency is present in the 23.4 version but not in 23.8, I don’t know for sure.

The only non-standard thing about the project is that I’m using a custom UiPath library, I tried re-compiling that with 23.8-beta, but I cannot publish any library to Orchestrator at all, including a blank new one (see logs below), so I maybe incompatibility with the library is the culprit. I tried deploying the library into a local feed and robot was unable to install it.

Anyways, the workaround I settled on is to use the Enterprise installer for version 23.4 and disable the auto updater service. Just copying the project and trying to run it in Studio 23.4 failed with the same error message, I used a backup to get the project to work again, although I suppose if you have the patience to tinker with the local folder and such you might be able to get it to work.

15:25:18.5767 => [ERROR] [UiPath.Studio] [1] Dispose-> RemoteExecute: connection lost in UiPath.Studio.Plugin.Workflow.AddInFramework.IAddInProjectEndpoint: System.IO.IOException: Connection closed.
at UiPath.CoreIpc.Connection.RemoteCall(Request request, Stream uploadStream, CancellationToken token)
at UiPath.CoreIpc.ServiceClient1.<>c__DisplayClass21_11.<b__1>d.MoveNext()
— End of stack trace from previous location —
at UiPath.CoreIpc.Helpers.Timeout[TResult](TimeSpan timeout, List1 cancellationTokens, Func2 func, String message, Func2 exceptionHandler) at UiPath.CoreIpc.ServiceClient1.<>c__DisplayClass21_11.<Invoke>b__2(Exception ex) at UiPath.CoreIpc.Helpers.Timeout[TResult](TimeSpan timeout, List1 cancellationTokens, Func2 func, String message, Func2 exceptionHandler)
at UiPath.Studio.Ipc.Shared.Services.IpcProxyBase1.RemoteExecute[T](Func2 remoteFunc, String callerName), HResult -2146232800
15:25:32.1671 => [ERROR] [UiPath.Studio] [1] Dispose-> RemoteExecute: connection lost in UiPath.Studio.Plugin.Workflow.AddInFramework.IAddInProjectEndpoint: System.IO.IOException: Connection closed.
at UiPath.CoreIpc.Connection.RemoteCall(Request request, Stream uploadStream, CancellationToken token)
at UiPath.CoreIpc.ServiceClient1.<>c__DisplayClass21_11.<b__1>d.MoveNext()
— End of stack trace from previous location —
at UiPath.CoreIpc.Helpers.Timeout[TResult](TimeSpan timeout, List1 cancellationTokens, Func2 func, String message, Func2 exceptionHandler) at UiPath.CoreIpc.ServiceClient1.<>c__DisplayClass21_11.<Invoke>b__2(Exception ex) at UiPath.CoreIpc.Helpers.Timeout[TResult](TimeSpan timeout, List1 cancellationTokens, Func2 func, String message, Func2 exceptionHandler)
at UiPath.Studio.Ipc.Shared.Services.IpcProxyBase1.RemoteExecute[T](Func2 remoteFunc, String callerName), HResult -2146232800
15:26:05.0753 => [ERROR] [UiPath.Studio.App.Logging.OutputLogger] [10] Error: Publish of Library project to Orchestrator failed. Package cannot be published to the shared feed
15:26:05.0755 => [ERROR] [UiPath.Studio] [10] Error: Publish of Library project to Orchestrator failed. Package cannot be published to the shared feed

[postwick (Paul Ostwick)]

@Stefan_Reutter

custom UiPath library

You mean one you developed? Make sure the dependencies in that library are all set to “Lowest Applicable Version”

[pikut]

If I created the nuget package from 23.10 Community Edition and will run it to other machine with Enterprise Edition, then process get fail before they even try start - return same error. How solution this issue, when CE do force update and EE do not have equal with CE version?

[Stefan_Reutter]

My work-around was to install Studio as a service and disable the UiPath Update service, this stops the forced update so I can have the same version installed

[pikut]

Maybe will be stupid question, but how You disable UiPath Update Service, because I can not do it. By Command Line?

[leonardo_correia_pimenta (Leonardo Pimenta)]

You need to update you studio version on production enviroment. The dev enviroment and production enviroment need to be with the same version.

Here i was with the same problem and after update the problem has gone.

[Paul_Piton]

Bonjour, je suis également embêter sur le même sujet que vous avez-vous trouvé une solution ? Merci beaucoup.

[Parvathy (PS Parvathy)]

Hi @Paul_Piton

Check the below thread.

Could not load type 'System.Activities.TextExpressionBase`1' from assembly 'UiPath.Workflow, Version=6.0.0.0, Culture=neutral, PublicKeyToken=null'

If you are using any package which is higher than any available in Enterprise version then it won’t work. Don’t use beta versions in Enterprise versions. If you lower the versions available to match with Enterprise and publish, it will work. Uninstall community version studio and install Enterprise dev studio and link with that Enterprise cloud orchestrator to resolve the issue. Enterprise studio is 2023.4.4.

This should help you

Regards

[Speziman]

I have the same issue in Enterprise environment.

I today installed the latest enterprise studio 23.10.4 and tried to release a project which worked before with Studio 23.4.5 to be released.

In our test system I encountered the above mentioned error. I must admit, that in the meantime I am very pissed from Windows projects in UiPath. This is not nearly as reliable and stable as the legacy ones.

[Jon_Smith]

This is an issue. Anything made with 23.10 doesn’t work in 23.4.

I have had to make sure I stick to 23.4 everywhere until we are ready to update everything to 23.10

The above users using Community are either using a community licence against the TOS or they for some reason are installing the community studio rather than an LTS release which is causing the issue.

I advice you keep everything on 23.4 until it can all be updated.

The System.Activities will also have issues if you use coded workflows in 23.4 but use the dependency of 23.10

[Shahyad_Sharghi]

I had the same issue in Azure DevOps pipeline
it didn’t work with the following

• task: UiPathInstallPlatform@4
  inputs:
  cliVersion: ‘WIN_23.6.8581.19168’

so I changed the cli version then it worked fine

• task: UiPathInstallPlatform@4
  inputs:
  cliVersion: ‘WIN_23.10.8753.32995’

[Rakshan_C_K]

Hey Stefan,

We encountered this at the end of 2023.
The developed code was running fine in the studio(22.12.0.0) but when it was published in the Client orchestrator and ran in using the assistant(22.10.4) it gave us an error stating - Could not load type ‘System.Activities.TextExpressionBase`1’ from assembly ‘UiPath.Workflow, Version=6.0.0.0, Culture=neutral, PublicKeyToken=null’.
Solution Implemented:

1. Please confirm that the Studio and assistant are in sync with a single version.
2. Due to the Auto-Update feature, the Development Machine Studio might get upgraded to the latest version, and the assistant in the client machine will still be present in its older version.
3. Try downgrading the studio version and packages to the selected version.
4. Later, you could try to publish and run the workflow in the assistant.

This fix helped us in resolving this issue.

Note: To Disable Auto-Update - Tenant > Manage Access > Choose Admin User>Edit>Update policy settings> None.

Thanks and Regards,
Rakshan C K