Same is happening to me.
When I created text outline.
When I go to overprint mode.
Not MAC.

Pedro, please share the exact specs of your OS and hardware (GPU included), along with the files you are having problems with.
Send this directly to the team at sharewithai@adobe.com
Please also mention this report’s link so they can track it back here — http://illustrator.uservoice.com/forums/601447/suggestions/50649197

After i updated to the new version of Illustrator 2026, when i try open old files that worked without any problem with the previous version, now i get this error "Can't finish previewing. Could not complete the requested operation" and cannot view the files. Need urgent Fix!

Jhonnatan, please share the file and your OS and GPU specifications, the Ai build number.
You can share it there in a comment if you are OK with having it public, or send it directly to the team, to sharewithai@adobe.com (in this case mention the link to this report, http://illustrator.uservoice.com/forums/601447/suggestions/50497011)

Esto sucede con mucha frecuencia! Da un poco de colera sabiendo que estoy pagando por un servicio

Facing the same issue in the latest version

Facing the same issue on 29.6.1

The file is not responding at all. I created it in the last Illustrator version, and it was totally fine. Now that I'm trying to work on it, the app is giving the attached message and goes outline.

This pattern stroke error is super annoying! I've run into this before and here's what usually works for me:
First thing - try hitting Ctrl+Y to switch to outline view, then you should be able to select the object and remove the pattern stroke. If that doesn't work, try Ctrl+A to select everything and then go to the Appearance panel and just delete the stroke with the pattern. https://homeracing.fr/
Sometimes I have to close other programs too because patterns on strokes eat up a ton of memory. Also try going to Effect > Document Raster Effects Settings and set it to 72 PPI - that usually helps with preview issues.

Last 10 to 11 Day i face the Problems

Please tell more about your hardware specs.
What Illustrator version are you using?
Does it help to toggle GPU/CPU modes?
Does it help with any file?

I just experienced this on my document. Using Adobe Illustrator 20204 v.28.7. Was applying a stroke on a shape and got the message "Can't finish previewing. Could not complete the requested operation." and the document turned into outlines. It fixed itself when I removed the stroke from that one shape and selected "Preview" in the "View". Not sure what caused it.

I added a 20% grey cmyk stroke to a rectangle and got this error. It was in an EPS file supplied by a customer. I'm using a

27" iMac 2017
4.2 GHz Quad-Core Intel Core i7
Radeon Pro 580 8 GB
64 GB 2400 MHz DDR4

I went to edit > undo, view > preview and it went back to how it was. I created a new rectangle and applied the strroke and no error. originally i was adding the stroke to a rectangle that already existed in the file.

Can you please share the file with the team for investigation? Email it to sharewithai@adobe.com and put the link to this report for tracking: http://illustrator.uservoice.com/forums/939477/suggestions/47244215
What is your OS? Your GPU? The GPU driver version? Other system details? The version of Ai you are using?
Does it help to remove some patterns? remove other objects?

When I have a file with multiple patterns in multiple places, save the file close out and when I reopen the file as soon as I move something or zoom in I get a prompt that "Can't finish previewing. Could not complete the requested operation"

이 문제가 아직도 해결되지 않았나요?
대용량의 인쇄물을 작업할 때 간혹 아웃라인만 남긴 채 미리보기를 로드 할 수 없는
문제를 작년에도 경험했습니다.

해결법은 프로그램을 종료 한 뒤, 상대적으로 저용량의 파일을 먼저 실행 후 대용량의 기존 파일을 여는 것이었습니다. 물론 작업이 지속적으로 진행 될 경우 미리보기를 로드 할 수 없는 문제는 여전했습니다. 게다가 runtime error 까지 뜨는 문제는 해결 될 기미가 전혀 보이지 않습니다.

I had the same problem on a customer-provided file at home. I needed to perform substantial edits to it, and had almost finished, when this happened.
System:
Windows 11 Pro
AMD Ryzen Threadripper Pro 3955wx
128GB 3200MHz DDR4
Nvidia RTX3090ti
4TB Seagate Firecuda 530 RAID10 root drive (4x 2TB)
4TB Seagate Firecuda 530 RAID10 file drive (4x 2TB)
400GB Intel DC 5800x scratch disk
Aside from that, now whenever I mouse over a path in this file, Illustrator freezes for about 10-60 seconds. On the computer I use at work, it would freeze for up to 3 minutes, and it crashed 3 times while trying to select anything at all.
I have tried going back to an earlier (functional) iteration of the file, and this eventually happens again. I tried to create a new file and selectively copy over paths, and this eventually happened again.

I ran into this issue today for the first time. I was working on a file on my iPad and Illustrator stopped registering changes to zoom/pan and I wasn't able to add anything to the document. Tried duplicating the file, tried removing all linked and embedded images, no dice. I opened it on my desktop (2019 Macbook Pro, macOS 11.6.2) and got the "Can't finish previewing" error. Really frustrating, I've been working on this project for weeks!

I updated Illustrator to version 26.1.0, but the problem was not solved. No moderator or administrator of this forum manages to give me an answer. If I create a pdf from Illustrator, then I open it with Acrobat, I can do any enlargement without any kind of problem.

[Ho aggiornato illustrator alla versione 26.1.0, ma il problema non è stato risolto.
Nessun moderatore oppure amministratore di questo forum riesce a darmi una risposta.
Se da illustrator creo un pdf, poi lo apro con Acrobat, posso fare qualsiasi ingrandimento senza alcun tipo di problema.]

Please install the latest version. I solved that problem. Thanks.