I have a KRA file with 1 raster layer and 1 group of 5 layers each one with a individual "Gauss blur" filter applied. When I select one of them and apply finally the transform to that layer (a 3D rotation), Krita show two progress bars (one for the layer and other for the filter applied to that layer), but when it reaches 33%, minutes passes without any change and, despite Krita responds, I can't save or "save as", so I finally must do a kill on Krita.

hi rafael

I can't reproduce the freeze, probably my test image is plain simple and prevents the problem you experience with your image.
The other reason might be the system or the krita version. Im on Linux, using 2.9 Pre-Alpha (git 5c27e26)

I hope you can resolve your problem.

Could you share your file with us? I'd like to try and reproduce the issue.

Yes, I have a new KRA file to share, and know exactly in what process it will fail. But I can't find in this forum how to attach files.

I would suggest using a dropbox link, or making a bug report on bugs.kde.org.

Well, I decided to share with SpiderOAK.

The first file
https://spideroak.com/share/INXW24DBOJ2GSZDPKNYGSZDFOJHUCSY/Images/home/rafael/P%C3%BAblico/Internet_Shared/Prueba_multifiltro_multicapa_2X3D_spin.kra is a simple three layers KRA file. Each layer have a blur gauss filter applied. That's fine, before you begin to play with "3D rotations" (select "Tranform" tool and hold Ctrl while you drag mouse near a side of the layer box). You can do it one, two times, but on third time, Krita will show that bar I mentioned, forever.

The second file
https://spideroak.com/share/INXW24DBOJ2GSZDPKNYGSZDFOJHUCSY/Images/home/rafael/P%C3%BAblico/Internet_Shared/Prueba_multifiltro_multicapa.kra is the same than the first file, but it have two times 3D rotated the layer named "hexagon", to make easy to reach the issue. As you can see (at leats, I see it that way) despite layer "Hexagon" is rotated about 45º two times (one in Y axis and one in X axis) that filter is applied only to "Blur gauss" filter layer!!! But that's another problem. The worst problem comes when you try to do a 3rd 3D rotation. Then it will try to do that rotation forever.

Let me know if you can't get to reproduce it.