When using Fabfilter plugins (as clip plugins) in WaveLab 12 Pro on a 4K display, the windows size keeps growing, and the scaling selected within the plugin is not kept.
Is this a Fabfffilter problem or a WaveLab bug?
Windows, Mac? No such problem with my Pro-Q 3 here.
You can select a preset size at the bottom right of the plugin. Did you do that?
Windows.
Yes, I did do that. It always keeps enlarging, even larger than the screen space.
My windows scaling is set to 149% (since one of my programs scales to 200% if I use 150%). Does the windows scale factor matter?
I would never use 149%. This is a door for problems because this is not standard at all. Probably some applications will make wrong computations because of rounding errors.
Thanks for the info. But does it affect my problem described above?
Probably yes.
This seems indeed to be the cause. On the other hand, Windows officially supports custom scaling factors, most programs work just fine, and therefore, it would be nice if WaveLab could handle them as well. 
Furthermore, most other plugins have no issues. So, it should be fixable.
Do you get the problem when using ‘standard’ scaling (125/150) too? If yes, then it is indeed a plugin problem. Leapwing had the same but fixed it, Softube are working on it, and some TDR plugins also exhibit this. It seems like the WL+Windows+scaling combo confuses some plugins, even if they work fine in Cubase. It’s very odd.
j,
150% indeed works better. Still, this is a WL issue that should be fixed.
Meanwhile, I am using a scale factor of 150%, but some plugins still cause problems.
For example, download the plugins from MeldaProduction Version 17 (there are free ones). If you resize these plugins by dragging in the lower-right corner, WL draws a window that is significantly larger than the actual plugin UI. And if you release the mouse button, the plugin will be fit into that too large window, WL assumes.
This looks like a WL bug to me.
I use a scale factor of 130% because I use a 42" 4K screen. I absolutely need to use a scale factor because it is not possible to mix or master properly with a screen too near, since acoustic reflections will cause dramatic comb filtering.
So I need the screen to be sufficiently far from my ears and speakers, and consequently, the screen is also far from my eyes, so characters needs to be bigger, especially that now I’m 48, and my eyes are not as good as they were, even with glasses.
The scale factor is creating several known problems on wavelab.
The first one (that I already signaled) created waveform innacuracy or waveform trembling when zooming on wavelab.
But it also create errating resing of plugins.
I encounter exactly the same problem as you for MeldaProduction plugins, they resize by factor 2 each time I close and reopen the plugin, so it’s impossible to work with.
It is really needed to fix this scaling issue on WL.
Please Philippe, try to do something about it…
Try a factor with a better rounding. 150% if possible or 125%. But 130% is not a good choice.