# Can't load a transform file

**URL:** https://discourse.itk.org/t/cant-load-a-transform-file/5984
**Category:** Beginner Questions
**Tags:** registration, python
**Created:** [June 9, 2023, 2:06am UTC](https://discourse.itk.org/t/cant-load-a-transform-file/5984 "2023-06-09T02:06:50Z")
**Posts on this page:** 1
**Page:** 1

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### Author: ![eddyod](https://discourse.itk.org/user_avatar/discourse.itk.org/eddyod/32/3480_2.png) [@eddyod](https://discourse.itk.org/u/eddyod)
#### Post date: [June 9, 2023, 2:06am UTC](https://discourse.itk.org/t/cant-load-a-transform-file/5984/1 "2023-06-09T02:06:50Z")

</div>

Hi,  
I’m trying to save and load a transform but keep getting an error when I try to open it:  
ITK ERROR: HDF5TransformIOTemplate(0x55708c136680): Could not create an instance of “MatrixOffsetTransformBase\_double\_3\_3”  
The usual cause of this error is not registering the transform with TransformFactory

Here is the relevant python code:

```py
fixedImage = itk.imread('fixed_file.tif', itk.F)
movingImage = itk.imread('moving_file.tif', itk.F)
init_transform = itk.VersorRigid3DTransform[itk.D].New() 
init_transform.SetIdentity()
transform_initializer = itk.CenteredVersorTransformInitializer[
type(fixedImage), type(movingImage)
].New()

transform_initializer.SetFixedImage(fixedImage)
transform_initializer.SetMovingImage(movingImage)
transform_initializer.SetTransform(init_transform)
transform_initializer.GeometryOn() 
transform_initializer.ComputeRotationOff() 
transform_initializer.InitializeTransform()
init_transform = init_transform.GetInverseTransform()
TRANSPATH = os.path.join(DATA, 'init-transform.h5')
itk.transformwrite([init_transform], TRANSPATH)
# saves the file
# now open in another program
saved_init_transform = itk.transformread(TRANSPATH)[0] # this causes the error

```