All, I was having this problem too on the latest version 25.1. I opened creative cloud, clicked on the ... to see other available versions, and reverted from the latest release to the one before. I restarted it and now running fine. There is a bug in rendering on the latest version that was killing my workflow. This was the only way to get back up and working quickly.

Detail: Mac OS, AI v 25.1

when we use a clipping mask, that effect gradient not directly affected on the mask shape, to see the effect we need to get out first, and move certain objects so that the results appear. this becomes ineffective if you have to get out of the clipping mask mode. idk if felt a bug when I started using Wacom to replace the mouse

Need Fix !

Hello, same problem here ! Very annoying. It slows down my creation process. We really need it it to be fixed !

Sme here, MacOS Catalina 10.15.7, Illustrator 2021

same

Whenever I apply an opacity mask, it's not working like it used to.
When I'm adding a shape or an fillin I don't get an realtime update. I have to switch out of mask mode into normal layout mode and deactivate and reactivate the layer to see the changes.
This issue is killing my workflow.

Yes I have the same issue in 25.1

Same problem for me. Mac OS 11.1, AI 25.1.

Editing Opacity Masks are a major issue. So much so, I never use them. Sometimes they just stop working.

Having the same issue with clipping masks. So frustrating.

same here.

Mac 10.15.7, Illustrator 25.1
Opacity mask doesn't redraw at all unless I release and remake the mask, or click twice on Clip or Invert Mask.

For people who rely on complex opacity masks this is devastating to workflow. It has quadrupled the time it takes to create the artwork that I do everyday.

Overall the newest update is the most glitchy version in years. Big time issues with clipping masks and opacity masks. Almost not even worth using.

On top of this 3 freezes which required entire system restarts in one day.

More little bugs here and there with GPU previewing (zooming, scrubbing, etc.) overall worst experience I have ever had with a same day Adobe update.

Same issue on my Windows 10 computer. I think this is a NEW BUG, wasn't there in previous versions.

Same with me on a new Mac w/BigSur 11.1

I have the same problem just now... What can I do too?

Hi

My Problem/Bug:

When I am in Opsity mask mode and add a gradient or an effect, I cannot see the result of the added effect / gradient.

To see a result, I have to turn the visibility of the layer off and then turn it back on.

What can I do?

Adobe Illustartor 2021 (25.1)

Illustrator 25.1 - Windows 10

Transparency Mask. Once you try to make changes to the mask, it does not show the changes live. You have to either 1) Click and unclick on the clip/invert mask option, 2) Turn Mask Off - then on, 3) View Outline - then back to Preview, or 4) Switch color modes and then go back.

Only then will the changes to the transparency mask show on the screen.

I've tried on two different computers and have had the same issue.