Digital Light & Color

While I was trying to reproduce the last problem posted by den, I seem to find an issue with the Mask transformation dialog. The attached print-screen in the den's post shows that there must have been at least three masks since the two mask thumbnails in the picture have gray title bars. Normally the mask created last keeps the title bar white.

So I opened the Mask transformation dialog and created three different masks using Brightness curve mask tool (have not tried others). Then I was alternately clicking the Edit... command from the context menu of each mask icon and at some point the third mask overlay failed to load or display in input image. Another Edit... command was then necessary.

Most of the time it happened like this:

Mask 1 - Edit..
Mask 2 - Edit..
Mask 3 - Edit.. and close the Mask 3 dialog
Mask 2 - Edit..
Mask 3 - Edit.. -> no mask overlay
Mask 3 - Edit.. -> overlay now loaded

And one more memory observation.
The first of the masks was mostly white so its loading was the longest with visible flashing of the curve status bar. This long loading repeated every time when the Mask 1 dialog was closed and reopened by Edit... command.
However when the Mask 1 dialog was not closed but replaced with Mask 2 or 3 mask dialog which was then closed, the Mask 1 dialog then opened immediately without any flashing:

Mask 1 Edit.. -> the Mask 1 dialog opened with visible flashing of the curve status bar, left open
Mask 2 or 3 Edit... the mask dialog opened and then closed
Mask 1 Edit.. -> opened immediately from the memory, no flashing

And finally a cosmetic one:
Except Reset the Setting commands in the Mask transformation dialog do not work. There is nothing else to set.

>> The first of the masks was mostly white so its loading was the longest with visible flashing of the curve status bar. This long loading repeated every time when the Mask 1 dialog was closed and reopened by Edit... command.
However when the Mask 1 dialog was not closed but replaced with Mask 2 or 3 mask dialog which was then closed, the Mask 1 dialog then opened immediately without any flashing:

If a transformation has multiple masks, each has its own mask dialog and several can be open simultaneously, but only one is visible at a time. To switch between them, you can click on the mask thumbnail in the image browser or, as you were doing, use Edit from the Amount control. When you close a mask dialog however, all of its intermediate states are discarded leaving only the final mask image. When you re-open the mask dialog with Edit, the intermediate masks are rebuilt by re-applying the individual mask operations sequentially.

I was not using any particular transformation. I was working only with the Masks transformation dialog using the masks similar to those visible in the attachment. I used the term transformarion only because the Masks dialog is located in the Transformation menu. It is more like a masks container then a transformation dialog. Sorry for the incorrect terminology.