Hi, I´m trying the last version of this awesome software , previously in a version before the 4.0 I saw that an animated layer with spot colors can duplicate it and turn it into a transparency mask to be able to apply shadows in a new layer, it worked perfectly when saving and opening the file (it is still possible to open it and reproduce without problem) but with the new version can be made but it is not recovered when opening the file again, the mask is empty completely blank, my question is if this question is a problem or there is a problem with this process, I hope someone can clarify this. I appreciate any help in this.

What was the 'old' version and what is the 'new' version and which OS are you using?
I've just tried this with version 4.2.2 and 4.2.3 on Windows 10 and on Linux and I had no problems creating, saving and reopening an animated transparency mask animation, even if the parent layer wasn't animated it still worked well.

Hi, thanks for the help, actually I´m working in Windows 7 (maybe it can be part of my problem xc ), and it worked in a version 3.1 I guess, and know I´ve tried in 4.2 (know 4.3) and previous version like 3.3, 4.0, and 4.1, without results.

It´s strange for me because in some versions the mask conserve data from 1 frame but it´s the same in all the timeline, and in others it´s completly in blank.
I´ll try in another pc, maybe it´s something in my config, and will try reintsall without previous data of Krita too.