ERROR - Robot Hangs with 2019 Version

Hi all, we recently upgraded from 2018.3.2 to 2019.4.2 both Studio and Orchestrator. We use Enterprise version on High Density Robot. HD Robot machhine (2012 R2) has 4 unattended robots. Workflows created on 2018 version were upgraded and published to orchestrator. But we see strange behaviors during execution of them. Robots simply start to produce strange errors. An example of our debugging:
WriteLine (“1”)
Take Screenshot
WriteLine (“2”)
Save Image
WriteLine (“3”)

What we see is the following:
WriteLine (“1”) happens at TimePoint 0 and then logging stops, robot stucks here.
After 15 minutes we manually RDP on that robot and suddenly it continues running.
Accoring to logs we see that the timestamps are the followings:
WriteLine (“1”) : BaseTime
Take Screenshot
WriteLine (“2”): When we opened an RDP to the robot
Save Image
WriteLine (“3”): Correct time after our RDP session.
Saved Image’s file time in windows explorer matches with the WriteLine(“3”) logentry’s time, so that seems OK.
But checking the Image it shows BaseTime+6 minutes on the screenshot (at the right bottom corner where the windows clock is).
So all together:
Workflow runs until it gets to a TakeScreenhot. It makes a screenshot after some minutes and does not continue until we RDP on the machine. After it works again well.
The problem is that we can not reoproduce it. It happens sometimes (too often) but this kills all of our jobs.
Another issue: sometimes we get “Cannot communicate with IE browser” error. Right after setting the Transaction to AppEx timeouts.
Any idea?

A new version (19.4.3) was just released, could you give it a try? On our side we no longer reproduce the problem.
Let me know if it is working.
Thank you,

Thanks, we have updated it and we will see tomorrow morning how the night batches will run. I’ll keep you informed.

Thanks, it seems to be OK. None of those errors occured again.
Thank you very much.

Hi, its been a quite a while hope you are seeing this…

I am facing the exact same issue as you. Did upgrading to 2019.4.3 help? as i upgraded to 2019.4.4 but still did not fix the hanging issue…


yes, 19.4.3 completely solved all of the strange issues and we still use that version, we haven’t upgraded to 19.4.4.
Before 19.4.3 was released, we made a fallback to 2018 last version and that was also working.


1 Like

Thank you for your response!

How about your Orchestrator version too? :slight_smile:

It also works well (Orchestrator 2019.4.2).
Only Studio/Robot 19.4.2. was problematic.


Thank you for your time! I tried to run with 2019.4.3 but problem is still happening with this version also. I am using azure virtual server to run my Bots in. All spec is good but I cannot understand why this is happening…

We have 2 robot machines, one in SoftLayer and another in Azure. Both were dying with 19.4.2 and both runs well with 19.4.3.
Have you adjusted the dependecies in your solutions? We use the following ones:
“UiPath.Credentials.Activities”: “[1.1.6479.13204]”,
“UiPath.Database.Activities”: “[1.2.6863.32528]”,
“UiPath.Excel.Activities”: “[2.5.3]”,
“UiPath.Mail.Activities”: “[1.4.0]”,
“UiPath.System.Activities”: “[19.4.0]”,
“UiPath.UIAutomation.Activities”: “[19.4.1]”,
“UiPath.WebAPI.Activities”: “[1.4.1]”

1 Like

Thank you. I am currently testing out 2018.4.2 which was released January this year. However it looks like its performing better than 2019.4.3 with 1000 more transactions to go for this test. Should be able to sort out the dependencies if it does hang again.

Hi @J_Swali

Could you give it a try with the latest Enterprise edition 2019.4.4:


I already have the issue still persists. I have a call with technical team today. Lets hope they can resolve this for me.

1 Like

I am also experiencing this right now. We are using 2019.4.4 Enterprise Version. Robot gets stuck randomly in different activities.
Tried reinstalling and deleting local logs or studio logs or even cleaning up orchestrator database logs but still get stuck randomly somewhere. Any fix?

Hi @dhennespiritu

I would advise you to contact our technical support.

You could also browse the Windows Event Viewer logs to see what happens when the robot freezes.

Where does it get stuck? i.e after what activity?