Version Issue (Development v 2018.3.3- Production 2018.2.3)

Hi All,

With regarding to the above topic, i would like to bring all your attention on this .
Recently we found one issue on the client tool, hence we started to fix the same.
After fixing the bug, we published the package… its not running on the production machine where as it is running well and good in the development.

Below error is what i found in the log,

Init - Error :System.Xaml.XamlObjectWriterException: Cannot set unknown member ‘UiPath.Core.Activities.ForEach(System.String).CurrentIndex’. at UiPath.Core.Activities.InvokeWorkflowFile.EndExecute(AsyncCodeActivityContext context, IAsyncResult result) at System.Activities.AsyncCodeActivity.System.Activities.IAsyncCodeActivity.FinishExecution(AsyncCodeActivityContext context, IAsyncResult result) at System.Activities.AsyncCodeActivity.CompleteAsyncCodeActivityData.CompleteAsyncCodeActivityWorkItem.Execute(ActivityExecutor executor, BookmarkManager bookmarkManager)"

level: “Error”

the version which i used in the development is 2018.3.3 in the production the bot is running with the version 2018.2.3

Kindly assist me on this as earliest as possible.


Hi @kumar12,

Check this,

@ SaranyaKishore,

Thanks for your reply,

I have tried upgrading the library, but its not working.


According to


Once a project is published with v2018.3 or higher, it can no longer be executed by using a v2018.2 or lower Robot.

I imagine if you look at the logs, when attempting to start the job/process, you’d see some errors about not being able to download the required package / versions.

Assuming you’re not on community, I’d put in a request for an older Studio installer version and reapply your fixes and republish. Alternatively see if upgrading Orchestrator and/or robots to 2018.3 or later is an option.

@ twhitehead,

Thanks for your reply,

i have one doubt, if i upgrade the robots and orchestrater to the latest version, whether it will not impact the bots which are developed with 2018.2.3 …


That would largely depend on your published packages and the activities that they are currently using. There is some additional reading linked off of that Core Activities Split page for “Legacy Processes” as well it would be good to review the Updating pages depending on which version you might consider upgrading to.

If still in doubt, I’d reach out to Support through their Online Support form.

From what I’ve read so far, it seems you either need to move backwards with the broken process, or forwards with everything else. I unfortunately cannot be more help then that as I jumped into UiPath starting with 2018.3.1 and have not had the pleasure of dealing with the migration when the activities were separated from the UiPath build.


Thanks once again,

I will inform the team to upgrade the orchestrator as well the bot running on the production for the latest version.

Have a nice day and great week ahead