This bug is back again for me.

Steps to repro:
Create new document
Add any kind of content (a single vertex will do)
Switch to Outline view - GPU is disabled
Switch back out of Outline view - GPU remains disabled
Saving and re-opening the document will re-enable GPU view, until outline is used again.

Win 10
Illustrator Version: 25.3
OpenGL Version: 4.6.0 NVIDIA 451.77
GeForce RTX 2060
32GB Ram

I am having similar issues with my GPU

Illustrator 25.2.3
OS : Windows 10

In the latest version (25.3 - Windows 10) after engaging Outline View (Ctrl-Y) the view now changes from GPU preview to CPU preview mode and will not revert to GPU preview mode until the file is closed and reopened.

Having the same problem with the GPU preview, it turns grey and can't go back to it after it happens, it renders the app useless.

Illustrator 25.2.3
OS: Mac OS Mojave
GPU: AMD Readeon Pro 580
RAM: 40 GB Memory

Hi,

Here is a screen recording of the bug that I can recreate every time.

1. Image in a linked file placed in AI
2. Mask the image with red box
3. Move image around artboard in real time. Using GPU
4. Double click into mask. Note: Screen goes black.
5. Double click back to artboard.
6. Move image around artboard in real time. GPU greyed out and very very slow.

I get in touch with Support, and interestingly enough they were able to help.

They said for unknown reason (yet) some older .ai files, and some specific content have this issue. Create a new document, and copy paste the content there, that solves my problem.

This is also happening to me

This is also happening for me.

Issue still exists, and it is really frustrating. Any zooming, movement, is just terrible slow...

Macbook Pro 13" (2018)
eGPU (Razer Core X + RX5600 XT)

This bug has been around for more than a month and is a critical workflow process bug and should be top priority. I'd like to think Adobe staff can empathize with tight deadlines that demand accuracy but seeing as this has been around for as long as it has, perhaps not. It's hard to not vilify this company for its severe lack of urgency.

I have received confirmation from Adobe (Twitter) that the steps I showed to create the bug were reproduced from the Adobe Team and that was about a month ago.

I'd like to see some transparency from Adobe and at least provide an update on what they've learned internally about this bug. This would at least restore a little bit of faith.

Update:
A few days ago I updated my MBP from Mojave to Big Sur. That didn't fix the issue.

MacBook Pro (15-inch, 2016)
2,7 GHz Quad-Core Intel Core i7
16 GB 2133 MHz LPDDR3
Radeon Pro 455 2 GB
Intel HD Graphics 530 1536 MB

This GPU-Bug is really crazy as it comes in so many incarnations. It seems, that nearly everybody has a slightly different scenario with this bug. I switched back to 25.0 as it seems (at least for me) to be the last working version regarding this bug. But using an old version while paying for the newest features can’t be the solution... ADOBE: FIX THIS! (and all the other bugs, before even thinking of implementing any new "fantastic" features)

Our department has all the exact same computers (iMac (Retina 5K, 27-inch, 2019)) and configurations (64 GB with 2 TB SSD). Three out of five have no issues and are running 25.2.1 without the GPU Render bug. Two out of five have the GPU Render bug. All computers are running the latest version of Catalina (our organization's current IT approved version). I have been through the settings on all the computers and they all match up exactly, from system settings to application settings. This is the most ridiculous bug I've ever seen (the same hardware and software configuration across computers should not have different results). The lack of attention this bug is receiving is appalling. The troubleshooting section for GPU Render in Illustrator on Adobe's site is for version 22.0. Do they even pay attention to the complaints? How can this still be an issue this long after release?

Currently, the two iMacs suffering from this bug are running 24.3 without issue (as far as GPU Render). I am currently running 25.0 on my effected iMac, but I had to start fresh and not transfer settings from previous version. I am still in the process of updating new document templates, setting up workspaces, etc.

Further, when I have 25.2.1 installed, if I use one of the included default document templates, GPU Render is active until I use cmd+R to turn on rulers. After that, GPU Render is deactivated and will not return for that document. I can make several new documents that have GPU Render active until I activate rulers. After an arbitrary number of newly created documents from default templates, it will not reactivate until the application is restarted.

During one day of troubleshooting about two months ago, the bug eventually caused 24.3 to have the same problem. I had to uninstall both 24 and 25 and completely nuke any trace of the settings in Preferences and Application Support folders for 24.3 to have GPU render functionality again. I'm not too keen on doing too much more troubleshooting, because I don't want to have to waste another half a day getting 24.3 to work should this happen again.

You don't need our screenshots, screen recordings, or steps. They have been laid out clearly for you in this thread. Your development team should be able to trace their steps between 25.0 and the next iterations which are having this issue in order to determine what they've changed which could have this effect. Stop stalling and do some work.

I'm also experiencing the problem on some files. All exports (JPEGs/PNGs and PDFs) out of Illustrator are appearing and printing darker. I've had to use a 2nd Mac (M1 Air Laptop) to open the file so VIEW USING GPU isn't greyed out. My company creates packaging for companys Kellogg's, Bayer and Pfizer and this issue is a pain ********** and needs to be fixed ASAP. Latest update from 2 days ago HASN'T resolved the issue.

ADOBE FIX YOUR ****! AFTER I FIND A WORK AROUND I'LL STOP DOING AUTO UPDATES. VERY UNPROFESSIONAL.

I'm glad I found this thread. I was having a similar issue. Starting a brand new file in Illustrator with GPU Preview enabled but then placing a jpeg I created in Photoshop caused the document to switch to CPU Preview (GPU greyed out). Reinstalled version 25.0 and it is fine.

I thought the issue was my monitor and/or my pantone swatches. I spent so much time adjusting the colours in my files before realizing it was the preview mode that was messed up. Frustrating!

I have been working on illustrator files containing vector & linked images, which have been used often in different files in the past. The ai file opens in CPU preview and cannot return to GPU.
I tried copying images from the CPU preview file to a new blank GPU preview file. While pasting an image, the preview turns to CPU. Even if the image is deleted, the preview does not return back to GPU. Same test with another artwork and another jpg.

Mojave 10.14.6
Ill version 25.2.1
GPU Performance Activated
AMD Radeon Pro 570X

Model Name: iMac
Model Identifier: iMac19,1
Processor Name: Intel Core i5
Processor Speed: 3 GHz
Number of Processors: 1
Total Number of Cores: 6
L2 Cache (per Core): 256 KB
L3 Cache: 9 MB
Memory: 8 GB

I'm experiencing a glitch when I switch between CPU and GPU preview.
Some parts of the graphics are blank and some images disappears.
All this when GPU preview is enabled.
When I switch tu CPU it's all fine.

I'm experiencing the same issue. I can replicate it from a blank document so hopefully this helps.

Once I place a linked .png or .gif file in the blank document GPU preview is disabled and is greyed out from the view menu.

I can place a linked .psd, .tif, and .jpg without any issue.

There are also certain older files that open up with the GPU preview disabled as well. Those files have embedded raster images.

My system specs are attached

Rainer, I've found that only v25.0.0 works for us. Give it a try.

Very similar problem here with both my Macbook Pro M1 and my iMac 2019 (i9, Vega48) with latest OS X Updates: Both machines lose GPU support when accessing a grouped elements, when turning on rulers or using guides. A document from scratch works just fine as long I don't do one of mentioned things above.

On the iMac I switched back to Ai 24 wich works fine. Ai 25 is a broken version.

Kind regards
Rainer