# Exception Caught in Thread Timer-20

**URL:** https://forum.universal-robots.com/t/exception-caught-in-thread-timer-20/11342
**Category:** Technical Questions
**Tags:** bugs
**Created:** [January 9, 2021, 12:47pm UTC](https://forum.universal-robots.com/t/exception-caught-in-thread-timer-20/11342 "2021-01-09T12:47:08Z")
**Posts on this page:** 1
**Page:** 1

<div class="post-metadata">

### Author: ![anon29970367](https://avatars.discourse-cdn.com/v4/letter/a/d2c977/32.png) [@anon29970367](https://forum.universal-robots.com/u/anon29970367)
#### Post date: [January 9, 2021, 12:47pm UTC](https://forum.universal-robots.com/t/exception-caught-in-thread-timer-20/11342/1 "2021-01-09T12:47:09Z")

</div>

# Summary

_Introduction to the issue_  
Robot is already installed at customer, but not yet used in production, so what exactly happened before is hard to estimate. After starting a cycle (externally from PLC) one of the robots did not move and the below shown message was visible on the teach pendant “ **Exception Caught in Thread Timer -20** ”.

# Versions

- Affected Robot Software Version(s): 5.9.4.1031232
- Affected Robot Hardware Version(s): eSeries
- Robot Serial Number: 20205001402
- UR+ product(s) installed: none
- URCaps Software version(s): none

# Impact

- not possible to play program

# Issue details

 ![WhatsApp Image 2021-01-08 at 17.43.30](https://us1.discourse-cdn.com/flex020/uploads/universal_robots/original/2X/8/8a449cffdf650db005ac608dd15d1a2b71f3faaf.jpeg)  
_This part is important in order to clarify the severity of the issue._

## Use Case and Setup

- Robot is used for screw driving application.

## Project status at point of discovered

- Before I started.

## Steps to Reproduce

- not able to reproduce the situation

## Workaround Suggestion

- Robot had to be restarted.