Synthesizing keys error

Scenario: Running robot that interacts with browser to copy some elements and download files randomly gets a “Synthetizing keys failure.” and terminates execution.

Steps to reproduce: Run a robot that interacts with browser on a loop until failure occurs.

Current Behavior: UiPath.Core.ElementOperationException: Write text failed. —> System.Runtime.InteropServices.COMException: Synthetizing keys failure.

at UiPath.UiNodeClass.WriteText(String text, UiInputMethod inputMethod)
at UiPath.Core.UiElement.WriteText(String text, InputMethod method)
— End of inner exception stack trace —
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)

Expected Behavior: Function normally, since the same code works most of the time, it randomly just does not work. There are no variable inputs in the ‘keys to be synthesized’, as this is pressing keyboard shortcuts to download files in IE.

Studio/Robot/Orchestrator Version: Studio 2017.1.6435

Last stable behavior: None
Last stable version: None
OS Version: Windows 7 Enterprise (6.1, build 7601, SP1)
Others if Relevant: (workflow, logs, .net version, service pack, etc):
.NET 4.0.30319.42000 (according to Studio)

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Haven’t come across this error before.:thinking:
However please try IE troubleshooting or change the browser to chrome(make sure to install extension).

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Yup, that’s what’s curious. IE troubleshooting seems to have no effect seeing as it works most of the time, but then after ~50 loops this happens. The browser is closed and reopened between loops.
Reworking to Chrome would probably involve a lot of changes, I’d rather find out why this is happening.
I can’t find anything regarding this, and seeing as the exception message even contains a typo (one extra t), it’s probably something unique to UiPath.
What has to fail for this message to be sent?

Looping #QA team. @Andrei_Pop


Is it failing always on the same activity and on the same web element?

Hi, not that I know of. Is there a way to catch which key is failing to be input?
It seems to not be a specific one.
Here’s a snippet of where it seems to be happening:

Any update on this?
This keeps happening quite often and restarting the robot every time it occurs isn’t such a great solution.
After this input, there’s a Alt+F4 that closes an open window.

I discovered that this may have a problem, seeing as the next time a Alt-key sensitive event happens in the loop the error occurs (all the other actions don’t seem to care if the button is held down). The image I posted last contains the first Alt-key sensitive input. Perhaps this is the problem?
The Alt key seems to get stuck down, instead of being released at the end of this.
Only tapping on the physical keyboard releases the key.

we need to know the activities that fail, can you rework the workflow and make it as small as possible, but still reproduce the error? (leave the minimum number of activities that generate the issue)
then, pass it to us to investigate?

you are running from Studio, right?
also, you can check the execution logs, clear everything from %localappdata%\UiPath\Logs and run again until you can reproduce

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i m gonna build a small workflow that sends hotkey to download something in IE and run it in a loop, see if i can reproduce

Yes, running from studio. I’ll create a minimal, complete and verifiable example.
I’ll check the logs.

Any update on this. I m also facing similar issue. Alt key locks down after loop on send hot key. And it happens only with Alt.


@anurag2708, Have you tried with Type Into ? Like [d(alt)]

Dominic :slight_smile:

can you try with 18.1? we have fixed this issue


Was it a known issue in previous version. Is there any fix or workaround for it in previous version.

Depends on your exact workflow, a workaround can be found.

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This error started since this morning for Alt+F4 SendHotKey Activity in production. It was working fine in 2017.1 since past 1 month.It is closing IE, but throwing an excpetion.


You are using 17.1.6435 right?
Update to latest 17.1 - sp2 or 18.1

No - 2017.1.6547 . Any idea why all of a sudden?

What is Sp2 version? 6612?


Yes, 6612. The occurence of that error is extremly low, 2-3 times in 1000 continuous runs especially on slow machines


Thanks! We run 4 cycles for a Citrix based bot in a day, we got 4 exceptions today each per cycle. We will monitor tomorrow and discuss internally regarding the upgrade or plan a workaround.