# Unit error when running an experiment

**URL:** https://discourse.psychopy.org/t/unit-error-when-running-an-experiment/12754
**Category:** Online experiments
**Tags:** screen, online, pavlovia
**Created:** [April 25, 2020, 8:35am UTC](https://discourse.psychopy.org/t/unit-error-when-running-an-experiment/12754 "2020-04-25T08:35:27Z")
**Posts on this page:** 2
**Page:** 1

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### Author: ![MDag97](https://avatars.discourse-cdn.com/v4/letter/m/45deac/32.png) [@MDag97](https://discourse.psychopy.org/u/MDag97)
#### Post date: [April 25, 2020, 8:35am UTC](https://discourse.psychopy.org/t/unit-error-when-running-an-experiment/12754/1 "2020-04-25T08:35:27Z")

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Repository URL: [Sign in · GitLab](https://gitlab.pavlovia.org/MDag/unibi_wm_task)  
OS: Windows 10  
Standalone version: Yes  
Using Builder to export to Pavlovia (It works fine when running it from python locally)

When I run the program online I go through the dialogue (enter participant number…) and then I get the following error message  
 ![image](https://us1.discourse-cdn.com/flex002/uploads/psychopy/original/3X/9/7/978f0bcd469ded8e21dec6c02ef398ff0ba7e8b6.png)

In the experiment settings the units are set to deg.

Any thoughts on how to solve this? Thanks!

Also - don’t know if it is helpful, but here is the output of the console in the browser, when the error occurs:

 ![image](https://us1.discourse-cdn.com/flex002/uploads/psychopy/original/3X/e/2/e26382f33d45ae458f1a449d24ed1b2cae6f708e.png)

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### Author: ![dvbridges](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.psychopy.org/dvbridges/32/1918_2.png) [@dvbridges](https://discourse.psychopy.org/u/dvbridges)
#### Post date: [April 25, 2020, 11:02am UTC](https://discourse.psychopy.org/t/unit-error-when-running-an-experiment/12754/2 "2020-04-25T11:02:39Z")

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@MDag97, I do not think you can use screen units of ‘deg’ in online studies because the degrees of visual angle is dependent on the distance of the participant from the screen, and the screen itself, things you cannot control in online studies - [see docs](https://www.psychopy.org/general/units.html#degrees-of-visual-angle). Use height or norm units to help with sizing for online tasks, because they are relative to the screen size.