# Minpack2 dll error

**URL:** <https://discourse.psychopy.org/t/minpack2-dll-error/18053>\
**Category:** Other\
**Created:** [November 12, 2020, 3:08am UTC](https://discourse.psychopy.org/t/minpack2-dll-error/18053 "2020-11-12T03:08:25Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![lazar](https://avatars.discourse-cdn.com/v4/letter/l/eada6e/32.png) [@lazar](https://discourse.psychopy.org/u/lazar)\
**Post date:** [November 12, 2020, 3:08am UTC](https://discourse.psychopy.org/t/minpack2-dll-error/18053/1 "2020-11-12T03:08:25Z")

</div>

running  
“C:\Program Files (x86)\PsychoPy3\pythonw.exe” “C:\Program Files (x86)\PsychoPy3\Lib\site-packages\psychopy\app\psychopyApp.py”

does not produce any output at all.

in trying to find the cause, I have started python and ran this  
from psychopy.app.\_psychopyApp import PsychoPyApp

which generated a buch of errors leading to this one:

> > > from scipy.optimize import minpack2  
> > > Traceback (most recent call last):  
> > > File “”, line 1, in   
> > > File “C:\Program Files (x86)\PsychoPy3\lib\site-packages\scipy\optimize\_\_init  
> > > \_\_.py”, line 386, in   
> > > from .optimize import \*  
> > > File “C:\Program Files (x86)\PsychoPy3\lib\site-packages\scipy\optimize\optimi  
> > > ze.py”, line 37, in   
> > > from .linesearch import (line\_search\_wolfe1, line\_search\_wolfe2,  
> > > File “C:\Program Files (x86)\PsychoPy3\lib\site-packages\scipy\optimize\linese  
> > > arch.py”, line 18, in   
> > > from scipy.optimize import minpack2  
> > > ImportError: DLL load failed: %1 is not a valid Win32 application.

any advice?

---

<div class="post-metadata">

**Author:** ![lazar](https://avatars.discourse-cdn.com/v4/letter/l/eada6e/32.png) [@lazar](https://discourse.psychopy.org/u/lazar)\
**Post date:** [November 16, 2020, 11:46pm UTC](https://discourse.psychopy.org/t/minpack2-dll-error/18053/2 "2020-11-16T23:46:03Z")

</div>

StandalonePsychoPy3\_PY2-3.2.4-win32.exe installs and works correctly  
StandalonePsychoPy3-2020.2.5-win32.exe installs but does not run at all.

Thus, maybe there are some dependency issues? Some libraries should be installed to make 2020.2.5 run?