# ALPACA error; Version 5.10.0 (stable)

**URL:** <https://discourse.slicer.org/t/alpaca-error-version-5-10-0-stable/46227>\
**Category:** Support\
**Created:** [February 20, 2026, 9:25am UTC](https://discourse.slicer.org/t/alpaca-error-version-5-10-0-stable/46227 "2026-02-20T09:25:22Z")\
**Posts on this page:** 11\
**Page:** 1

<div class="post-metadata">

**Author:** ![juliangallaun](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/juliangallaun/32/9545_2.png) [@juliangallaun](https://discourse.slicer.org/u/juliangallaun)\
**Post date:** [February 20, 2026, 9:25am UTC](https://discourse.slicer.org/t/alpaca-error-version-5-10-0-stable/46227/1 "2026-02-20T09:25:22Z")

</div>

![Screenshot_alpaca_error](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/2/2/22ea63882bcf80b0940b9d637f745a5123720322.jpeg)

Hello all,

I have a problem opening the ALPACA extension, with the stable version of 3D slicer 5.10.0 .

The error code says, it can’t find a certain file. I should have installed all additional extensions to run the extension. I reinstalled the extension again, without solving the problem. On the version 5.8.1 ALPACA works on my device.

Thank you for your help and advice.

---

<div class="post-metadata">

**Author:** ![drnoorfatima](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/drnoorfatima/32/81980_2.png) [@drnoorfatima](https://discourse.slicer.org/u/drnoorfatima)\
**Post date:** [February 20, 2026, 10:29am UTC](https://discourse.slicer.org/t/alpaca-error-version-5-10-0-stable/46227/2 "2026-02-20T10:29:40Z")

</div>

Hi!

The issue is a missing itk Python package in Slicer 5.10.0’s environment. Open the Python Interactor in Slicer and run:

slicer.util.pip\_install(‘itk’)

Then restart Slicer and try opening ALPACA again. That should fix it!

---

<div class="post-metadata">

**Author:** ![juliangallaun](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/juliangallaun/32/9545_2.png) [@juliangallaun](https://discourse.slicer.org/u/juliangallaun)\
**Post date:** [February 20, 2026, 10:58am UTC](https://discourse.slicer.org/t/alpaca-error-version-5-10-0-stable/46227/3 "2026-02-20T10:58:01Z")

</div>

![Screenshot_alpaca_error1](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/f/c/fce8bae70387ab958e80d8bb49087b3f62ac4c08.jpeg)

I did run the command and this was the reply. Nothing changed regarding the problem.

---

<div class="post-metadata">

**Author:** ![muratmaga](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/muratmaga/32/3622_2.png) [@muratmaga](https://discourse.slicer.org/u/muratmaga)\
**Post date:** [February 20, 2026, 4:43pm UTC](https://discourse.slicer.org/t/alpaca-error-version-5-10-0-stable/46227/4 "2026-02-20T16:43:39Z")

</div>

It appears your slicer 5.10 installation is problematic for some reason. E.g., the real issue is the first error (Application Does Not exist).

I suggest freshly installing it to a new place (like your desktop), install SlicerMorph and retry.

---

<div class="post-metadata">

**Author:** ![juliangallaun](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/juliangallaun/32/9545_2.png) [@juliangallaun](https://discourse.slicer.org/u/juliangallaun)\
**Post date:** [February 20, 2026, 5:00pm UTC](https://discourse.slicer.org/t/alpaca-error-version-5-10-0-stable/46227/5 "2026-02-20T17:00:22Z")

</div>

Ok, I did that and got the exact same error as the first time.

I did save it on the desktop as you suggested.

---

<div class="post-metadata">

**Author:** ![muratmaga](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/muratmaga/32/3622_2.png) [@muratmaga](https://discourse.slicer.org/u/muratmaga)\
**Post date:** [February 20, 2026, 7:15pm UTC](https://discourse.slicer.org/t/alpaca-error-version-5-10-0-stable/46227/6 "2026-02-20T19:15:49Z")

</div>

what happens when you do the `pip_install(“itk”)`

---

<div class="post-metadata">

**Author:** ![juliangallaun](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/juliangallaun/32/9545_2.png) [@juliangallaun](https://discourse.slicer.org/u/juliangallaun)\
**Post date:** [February 23, 2026, 2:25pm UTC](https://discourse.slicer.org/t/alpaca-error-version-5-10-0-stable/46227/7 "2026-02-23T14:25:34Z")

</div>

The second screenshot shows just that or did I do something wrong? It says the Application does not exist.

---

<div class="post-metadata">

**Author:** ![muratmaga](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/muratmaga/32/3622_2.png) [@muratmaga](https://discourse.slicer.org/u/muratmaga)\
**Post date:** [February 23, 2026, 5:07pm UTC](https://discourse.slicer.org/t/alpaca-error-version-5-10-0-stable/46227/8 "2026-02-23T17:07:39Z")

</div>

I think there is something weird going on with your installation, though don’t know why. I am going to assume you will get the same problem if you try to pip install another package, like `pip_install(“scipy”)`

---

<div class="post-metadata">

**Author:** ![juliangallaun](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/juliangallaun/32/9545_2.png) [@juliangallaun](https://discourse.slicer.org/u/juliangallaun)\
**Post date:** [February 23, 2026, 5:21pm UTC](https://discourse.slicer.org/t/alpaca-error-version-5-10-0-stable/46227/9 "2026-02-23T17:21:55Z")

</div>

Yes, the same error occurs. The Application does not exist.

---

<div class="post-metadata">

**Author:** ![muratmaga](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/muratmaga/32/3622_2.png) [@muratmaga](https://discourse.slicer.org/u/muratmaga)\
**Post date:** [February 23, 2026, 5:37pm UTC](https://discourse.slicer.org/t/alpaca-error-version-5-10-0-stable/46227/10 "2026-02-23T17:37:30Z")

</div>

I don’t why. I Just did a fresh install of a 5.10 package I downloaded from [download.slicer.org](http://download.slicer.org), installed SlicerMorph and run ALPACA on my windows computer and everything worked as expected. I wonder if you have antivirus or centrally managed something that removes files. All I can say maybe try with a different computer

```auto
Python 3.12.10 (main, Feb 12 2026, 15:11:32) [MSC v.1944 64 bit (AMD64)] on win32
>>> 
[Qt] libpng warning: iCCP: profile 'ICC Profile': 'CMYK': invalid ICC profile color space
[Qt] libpng warning: iCCP: known incorrect sRGB profile
Collecting mistune
  Downloading mistune-3.2.0-py3-none-any.whl.metadata (1.9 kB)
Downloading mistune-3.2.0-py3-none-any.whl (53 kB)
Installing collected packages: mistune
Successfully installed mistune-3.2.0
Collecting itk~=5.4.0
  Downloading itk-5.4.5-cp311-abi3-win_amd64.whl.metadata (22 kB)
Collecting itk-core==5.4.5 (from itk~=5.4.0)
  Downloading itk_core-5.4.5-cp311-abi3-win_amd64.whl.metadata (22 kB)
Collecting itk-numerics==5.4.5 (from itk~=5.4.0)
  Downloading itk_numerics-5.4.5-cp311-abi3-win_amd64.whl.metadata (22 kB)
Collecting itk-io==5.4.5 (from itk~=5.4.0)
  Downloading itk_io-5.4.5-cp311-abi3-win_amd64.whl.metadata (22 kB)
Collecting itk-filtering==5.4.5 (from itk~=5.4.0)
  Downloading itk_filtering-5.4.5-cp311-abi3-win_amd64.whl.metadata (22 kB)
Collecting itk-registration==5.4.5 (from itk~=5.4.0)
  Downloading itk_registration-5.4.5-cp311-abi3-win_amd64.whl.metadata (22 kB)
Collecting itk-segmentation==5.4.5 (from itk~=5.4.0)
  Downloading itk_segmentation-5.4.5-cp311-abi3-win_amd64.whl.metadata (22 kB)
Requirement already satisfied: numpy in c:\users\amaga\desktop\3d slicer 5.10.0\lib\python\lib\site-packages (from itk~=5.4.0) (2.0.2)
Downloading itk-5.4.5-cp311-abi3-win_amd64.whl (16 kB)
Downloading itk_core-5.4.5-cp311-abi3-win_amd64.whl (37.4 MB)
   ---------------------------------------- 37.4/37.4 MB 17.5 MB/s eta 0:00:00
Downloading itk_filtering-5.4.5-cp311-abi3-win_amd64.whl (23.6 MB)
   ---------------------------------------- 23.6/23.6 MB 17.4 MB/s eta 0:00:00
Downloading itk_io-5.4.5-cp311-abi3-win_amd64.whl (8.7 MB)
   ---------------------------------------- 8.7/8.7 MB 14.6 MB/s eta 0:00:00
Downloading itk_numerics-5.4.5-cp311-abi3-win_amd64.whl (19.7 MB)
   ---------------------------------------- 19.7/19.7 MB 20.8 MB/s eta 0:00:00
Downloading itk_registration-5.4.5-cp311-abi3-win_amd64.whl (9.5 MB)
   ---------------------------------------- 9.5/9.5 MB 13.8 MB/s eta 0:00:00
Downloading itk_segmentation-5.4.5-cp311-abi3-win_amd64.whl (5.0 MB)
   ---------------------------------------- 5.0/5.0 MB 23.5 MB/s eta 0:00:00
Installing collected packages: itk-core, itk-numerics, itk-io, itk-filtering, itk-segmentation, itk-registration, itk

Successfully installed itk-5.4.5 itk-core-5.4.5 itk-filtering-5.4.5 itk-io-5.4.5 itk-numerics-5.4.5 itk-registration-5.4.5 itk-segmentation-5.4.5
Collecting scikit-learn
  Downloading scikit_learn-1.8.0-cp312-cp312-win_amd64.whl.metadata (11 kB)
Requirement already satisfied: numpy>=1.24.1 in c:\users\amaga\desktop\3d slicer 5.10.0\lib\python\lib\site-packages (from scikit-learn) (2.0.2)
Requirement already satisfied: scipy>=1.10.0 in c:\users\amaga\desktop\3d slicer 5.10.0\lib\python\lib\site-packages (from scikit-learn) (1.13.1)
Collecting joblib>=1.3.0 (from scikit-learn)
  Downloading joblib-1.5.3-py3-none-any.whl.metadata (5.5 kB)
Collecting threadpoolctl>=3.2.0 (from scikit-learn)
  Using cached threadpoolctl-3.6.0-py3-none-any.whl.metadata (13 kB)
Downloading scikit_learn-1.8.0-cp312-cp312-win_amd64.whl (8.0 MB)
   ---------------------------------------- 8.0/8.0 MB 82.5 MB/s eta 0:00:00
Downloading joblib-1.5.3-py3-none-any.whl (309 kB)
Using cached threadpoolctl-3.6.0-py3-none-any.whl (18 kB)
Installing collected packages: threadpoolctl, joblib, scikit-learn

Successfully installed joblib-1.5.3 scikit-learn-1.8.0 threadpoolctl-3.6.0
Collecting itk-fpfh~=0.2.0
  Downloading itk_fpfh-0.2.1-cp311-abi3-win_amd64.whl.metadata (16 kB)
Requirement already satisfied: itk==5.4.* in c:\users\amaga\desktop\3d slicer 5.10.0\lib\python\lib\site-packages (from itk-fpfh~=0.2.0) (5.4.5)
Requirement already satisfied: itk-core==5.4.5 in c:\users\amaga\desktop\3d slicer 5.10.0\lib\python\lib\site-packages (from itk==5.4.*->itk-fpfh~=0.2.0) (5.4.5)
Requirement already satisfied: itk-numerics==5.4.5 in c:\users\amaga\desktop\3d slicer 5.10.0\lib\python\lib\site-packages (from itk==5.4.*->itk-fpfh~=0.2.0) (5.4.5)
Requirement already satisfied: itk-io==5.4.5 in c:\users\amaga\desktop\3d slicer 5.10.0\lib\python\lib\site-packages (from itk==5.4.*->itk-fpfh~=0.2.0) (5.4.5)
Requirement already satisfied: itk-filtering==5.4.5 in c:\users\amaga\desktop\3d slicer 5.10.0\lib\python\lib\site-packages (from itk==5.4.*->itk-fpfh~=0.2.0) (5.4.5)
Requirement already satisfied: itk-registration==5.4.5 in c:\users\amaga\desktop\3d slicer 5.10.0\lib\python\lib\site-packages (from itk==5.4.*->itk-fpfh~=0.2.0) (5.4.5)
Requirement already satisfied: itk-segmentation==5.4.5 in c:\users\amaga\desktop\3d slicer 5.10.0\lib\python\lib\site-packages (from itk==5.4.*->itk-fpfh~=0.2.0) (5.4.5)
Requirement already satisfied: numpy in c:\users\amaga\desktop\3d slicer 5.10.0\lib\python\lib\site-packages (from itk==5.4.*->itk-fpfh~=0.2.0) (2.0.2)
Downloading itk_fpfh-0.2.1-cp311-abi3-win_amd64.whl (459 kB)
Installing collected packages: itk-fpfh
Successfully installed itk-fpfh-0.2.1
Collecting itk-ransac~=0.2.1
  Downloading itk_ransac-0.2.1-cp311-abi3-win_amd64.whl.metadata (17 kB)
Requirement already satisfied: itk==5.4.* in c:\users\amaga\desktop\3d slicer 5.10.0\lib\python\lib\site-packages (from itk-ransac~=0.2.1) (5.4.5)
Requirement already satisfied: itk-core==5.4.5 in c:\users\amaga\desktop\3d slicer 5.10.0\lib\python\lib\site-packages (from itk==5.4.*->itk-ransac~=0.2.1) (5.4.5)
Requirement already satisfied: itk-numerics==5.4.5 in c:\users\amaga\desktop\3d slicer 5.10.0\lib\python\lib\site-packages (from itk==5.4.*->itk-ransac~=0.2.1) (5.4.5)
Requirement already satisfied: itk-io==5.4.5 in c:\users\amaga\desktop\3d slicer 5.10.0\lib\python\lib\site-packages (from itk==5.4.*->itk-ransac~=0.2.1) (5.4.5)
Requirement already satisfied: itk-filtering==5.4.5 in c:\users\amaga\desktop\3d slicer 5.10.0\lib\python\lib\site-packages (from itk==5.4.*->itk-ransac~=0.2.1) (5.4.5)
Requirement already satisfied: itk-registration==5.4.5 in c:\users\amaga\desktop\3d slicer 5.10.0\lib\python\lib\site-packages (from itk==5.4.*->itk-ransac~=0.2.1) (5.4.5)
Requirement already satisfied: itk-segmentation==5.4.5 in c:\users\amaga\desktop\3d slicer 5.10.0\lib\python\lib\site-packages (from itk==5.4.*->itk-ransac~=0.2.1) (5.4.5)
Requirement already satisfied: numpy in c:\users\amaga\desktop\3d slicer 5.10.0\lib\python\lib\site-packages (from itk==5.4.*->itk-ransac~=0.2.1) (2.0.2)
Downloading itk_ransac-0.2.1-cp311-abi3-win_amd64.whl (545 kB)
   --------------------------------------- 545.1/545.1 kB 17.7 MB/s eta 0:00:00
Installing collected packages: itk-ransac
Successfully installed itk-ransac-0.2.1
Collecting cpdalp
  Downloading cpdalp-1.2.0-py3-none-any.whl.metadata (2.8 kB)
Requirement already satisfied: numpy in c:\users\amaga\desktop\3d slicer 5.10.0\lib\python\lib\site-packages (from cpdalp) (2.0.2)
Downloading cpdalp-1.2.0-py3-none-any.whl (18 kB)
Installing collected packages: cpdalp
Successfully installed cpdalp-1.2.0
Collecting pandas
  Downloading pandas-3.0.1-cp312-cp312-win_amd64.whl.metadata (19 kB)
Requirement already satisfied: numpy>=1.26.0 in c:\users\amaga\desktop\3d slicer 5.10.0\lib\python\lib\site-packages (from pandas) (2.0.2)
Requirement already satisfied: python-dateutil>=2.8.2 in c:\users\amaga\desktop\3d slicer 5.10.0\lib\python\lib\site-packages (from pandas) (2.9.0.post0)
Collecting tzdata (from pandas)
  Downloading tzdata-2025.3-py2.py3-none-any.whl.metadata (1.4 kB)
Requirement already satisfied: six>=1.5 in c:\users\amaga\desktop\3d slicer 5.10.0\lib\python\lib\site-packages (from python-dateutil>=2.8.2->pandas) (1.17.0)
Downloading pandas-3.0.1-cp312-cp312-win_amd64.whl (9.7 MB)
   ---------------------------------------- 9.7/9.7 MB 100.8 MB/s eta 0:00:00
Downloading tzdata-2025.3-py2.py3-none-any.whl (348 kB)
Installing collected packages: tzdata, pandas

Successfully installed pandas-3.0.1 tzdata-2025.3

```

---

<div class="post-metadata">

**Author:** ![juliangallaun](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/juliangallaun/32/9545_2.png) [@juliangallaun](https://discourse.slicer.org/u/juliangallaun)\
**Post date:** [February 23, 2026, 5:42pm UTC](https://discourse.slicer.org/t/alpaca-error-version-5-10-0-stable/46227/11 "2026-02-23T17:42:47Z")

</div>

You were right my antivirus was the cause of the problem now everything works fine.