# Internal error on a new computer

**URL:** <https://discourse.psychopy.org/t/internal-error-on-a-new-computer/17241>\
**Category:** Builder\
**Created:** [October 14, 2020, 2:49am UTC](https://discourse.psychopy.org/t/internal-error-on-a-new-computer/17241 "2020-10-14T02:49:12Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![shirtzi](https://avatars.discourse-cdn.com/v4/letter/s/58f4c7/32.png) [@shirtzi](https://discourse.psychopy.org/u/shirtzi)\
**Post date:** [October 14, 2020, 2:49am UTC](https://discourse.psychopy.org/t/internal-error-on-a-new-computer/17241/1 "2020-10-14T02:49:12Z")

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**OS** ( Win10):  
**PsychoPy version** (2020-2.4):  
**Standard Standalone? (y)**

Hi,

I installed Psychopy and Python 3.9 on a new computer, and open an experiment that was built in an older version.  
When I tried to run it online I received this error msg:

Traceback (most recent call last):  
File “C:\Program Files\PsychoPy3\lib\site-packages\psychopy\app\builder\builder.py”, line 1240, in onPavloviaRun  
self.fileExport(htmlPath=self.\_getHtmlPath(self.filename))  
File “C:\Program Files\PsychoPy3\lib\site-packages\psychopy\app\builder\builder.py”, line 719, in fileExport  
target=“PsychoJS”)  
File “C:\Program Files\PsychoPy3\lib\site-packages\psychopy\scripts\psyexpCompile.py”, line 73, in generateScript  
compileScript(infile=exp, version=None, outfile=filename)  
File “C:\Program Files\PsychoPy3\lib\site-packages\psychopy\scripts\psyexpCompile.py”, line 242, in compileScript  
\_makeTarget(thisExp, outfile, targetOutput)  
File “C:\Program Files\PsychoPy3\lib\site-packages\psychopy\scripts\psyexpCompile.py”, line 214, in \_makeTarget  
script = thisExp.writeScript(outfile, target=targetOutput, modular=True)  
File “C:\Program Files\PsychoPy3\lib\site-packages\psychopy\experiment\_experiment.py”, line 251, in writeScript  
self\_copy.\_currentRoutine.writeRoutineBeginCodeJS(script, modular)  
File “C:\Program Files\PsychoPy3\lib\site-packages\psychopy\experiment\routine.py”, line 277, in writeRoutineBeginCodeJS  
thisCompon.writeRoutineStartCodeJS(buff)  
File “C:\Program Files\PsychoPy3\lib\site-packages\psychopy\experiment\components\_base.py”, line 202, in writeRoutineStartCodeJS  
self.writeParamUpdatesJS(buff, ‘set every repeat’)  
File “C:\Program Files\PsychoPy3\lib\site-packages\psychopy\experiment\components\_base.py”, line 405, in writeParamUpdatesJS  
target=“PsychoJS”)  
File “C:\Program Files\PsychoPy3\lib\site-packages\psychopy\experiment\components\_base.py”, line 399, in writeParamUpdates  
target=target)  
File “C:\Program Files\PsychoPy3\lib\site-packages\psychopy\experiment\components\_base.py”, line 435, in writeParamUpdate  
valStr = str(val).strip()  
TypeError: **str** returned non-string (type NoneType)

Tnx in advanced,

Shira

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<div class="post-metadata">

**Author:** ![TParsons](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.psychopy.org/tparsons/32/8301_2.png) [@TParsons](https://discourse.psychopy.org/u/TParsons)\
**Post date:** [October 16, 2020, 9:48am UTC](https://discourse.psychopy.org/t/internal-error-on-a-new-computer/17241/2 "2020-10-16T09:48:25Z")

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These errors happen when the value of one of your parameters cannot be converted to a string - usually because it doesn’t exist or shares a name with something else (e.g. a base Python function or the name of another component, parameter, etc.) so is overwritten

If you share the `.psyexp` file then I can use dev tools to track it down, this has popped up a few times so I’ve added in some code for the next version to add more information to the error message, hopefully making this easier to track down in future!