Thumbnails glitching when saved
Randomly, when files and thumbnails are saved out of Illustrator, the resulting thumbnails are glitched in a variety of ways. This glitch is present in the preview in the Finder window, but upon opening the file again, the glitch is not present. This is not from appearances or overprint being applied to artwork elements, as we are familiar with the issues those settings present in a print production environment, and this is a separate issue.
- Running on a MacBook Pro, 2021, running Sequoia 15.0.
- Using Illustrator 30.0.
- The issue occurs when Illustrator saves a file or thumbnail, randomly, without any indicators that it's going to happen.
- The preview of the file and the thumbnails of the file should match exactly how the file appears in Illustrator, but the saved -preview and thumbnails appear glitched in some way.
A) In the orange file example, the file is saved exactly as shown in screenshot A1. The thumbnail and preview of the file were saved with elements duplicated and scaled differently from the actual file and how the actual file appears when reopened—screenshot A2 and A3. I do not have the original file with the issue to attach.
B) In the Super Collagen file, the file was saved exactly as shown in screenshot B1. The thumbnail and preview of the file were saved with multiple elements missing and without the background elements—screenshot B2.
C) In the Smooth Current Serum file, the file was saved exactly as shown in screenshot C1. The thumbnail and preview of the file were saved with a previous version of the "SMOOTH" text overlapping the actual text in the artwork. This old version had 3 "O's" in the text, but was DELETED/removed from the file. Yet it saved over top of the corrected version in the thumbnail and preview, even though this "SMOOOTH" text had been deleted PRIOR to saving the file.
These issues cause huge problems in a production environment when the thumbnails are used for proofing and the software saving out the thumbnails cannot be trusted to accurately represent the artwork. I have screenshots and files for about 15 additional documented instances of this thumbnail/preview glitch occurring.
The same issue appears to have been reported to the r/AdobeIllustrator thread on reddit a month ago. https://www.reddit.com/r/AdobeIllustrator/comments/1okei68/anyone_else_getting_glitched_previews_for_ai/
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monokano
commented
The new background save method "Quick Save" in Illustrator 2026 (30.0) was causing malformed compatible PDF generation. It had actually been silently implemented in 2025 (29) as well, triggering the same bug.
This issue was fixed in 2026 (30.1) and 2025 (29.8.4). However, the problems that background saving has had since 2020 (24) still appear to persist.
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monokano
commented
Illustrator files have two types of previews: "bitmap image" and "compatible PDF data." The issue being discussed here concerns the compatible PDF.
Compatible PDF is not just used for previews — it serves as actual working data in many contexts, including linked placement in InDesign documents, import into After Effects, and more. It is a critically important component of the file.
Compatible PDF must be generated with an appearance that is completely identical to the native data when saving an .ai file. However, ever since the background save feature was introduced, there has been a long-standing bug where the compatible PDF is generated with a different appearance. Moreover, because it occurs randomly, the exact conditions that trigger it cannot be determined.
Some users have learned through experience that disabling the background save feature prevents this issue.
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Thanks for confirmation Camille. In one of your comments made on January 13, 2026, you attached a screenshot showing Ai file when opened, Ai file preview in Finder and preview of a PNG file (created from Ai file) in Finder.
In that screenshot, only PNG file's preview was glitched. Is that a right understanding? Or, do you see Ai file preview in Finder as glitched as well?
Is it possible for you to share any such Ai file with us at sharewithai@adobe.com? Do mention the link of this thread (https://illustrator.uservoice.com/forums/601447/suggestions/50776133) in the subject of email.
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From Camille
To Akshaya Saxena: Yes, the issue is occurring regularly. The file itself is intact, but the thumbnail and the preview in the Finder window appear glitched. Embedding the placed file does not seem to resolve the issue.
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Camille,
Is the incorrect thumbnail issue happening regularly at your end? The fix mentioned for this post is for the original issue of duplication of layers. In your case, the Illustrator file itself is correct but the thumbnail is glitched? Is that correct understanding of the issue?
You also mentioned that when you place this file into another Illustrator document, you run into same issue. Does embedding the file after placing corrects the problem?
(Edited by admin) -
Camille Stewart commented
Can the fix for this issue please be included in the next Illustrator update? This problem is causing daily issues for the graphics department of my company and is very frustrating to have to constantly fix. The attached image shows another example of the incorrect thumbnail being created from the file. It is disappointing that the fix has only been deployed for the Beta version as I am not able to use the Beta version with my company's software.
(Edited by admin) -
This issue has not been fixed in the latest Illustrator release: 30.1.
Though the file appears correctly in the thumbnail of the file itself within the Finder window, the thumbnail created from the design displays the scaling issue that interferes with my workflow, shown in the middle Finder window in the screenshot. The bottom finder window shows the file preview, and the file is shown open in Illustrator in the background.
If the file is placed into another Illustrator document, which is how my team's workflow works, the issue persists, meaning it would print this way.(Edited by admin)
