# Cannot apply any filter
**URL:** https://discourse.paraview.org/t/cannot-apply-any-filter/7874
**Category:** ParaView Support
**Created:** [August 27, 2021, 3:53am UTC](https://discourse.paraview.org/t/cannot-apply-any-filter/7874 "2021-08-27T03:53:49Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@1113](https://discourse.paraview.org/u/1113)
#### Post date: [August 27, 2021, 3:53am UTC](https://discourse.paraview.org/t/cannot-apply-any-filter/7874/1 "2021-08-27T03:53:49Z")
Hi,
I imported segmentation file from itk-SNAP in vtk format in Paraview(ver 5.9.1).
Every filter looks in gray and is not applicable to my model
Also when I put the cursor on contour filter icon, ‘Requires an input’ message shows.
How can it be fixed? Specifically I want to apply contour filter to my model.
Is it the problem of my file?
Thank you in advance.
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### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [August 27, 2021, 9:59am UTC](https://discourse.paraview.org/t/cannot-apply-any-filter/7874/2 "2021-08-27T09:59:30Z")
Press apply.
> [@I've just opened my dataset. I can't add filters, and everything is greyed out](https://discourse.paraview.org/t/ive-just-opened-my-dataset-i-cant-add-filters-and-everything-is-greyed-out/4511):
>
> Make sure your dataset is selected in the Pipeline Browser Click apply (in the Properties tab) if the apply button is green
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### Author:  [@1113](https://discourse.paraview.org/u/1113)
#### Post date: [August 27, 2021, 6:56pm UTC](https://discourse.paraview.org/t/cannot-apply-any-filter/7874/3 "2021-08-27T18:56:08Z")
Thanks so much 😅 🙂